ALBERT

Notes: C 2 continuous convexity-preserving parametric curves in ℝ2 is presented. The control point form method, which was developed in the field of numerical grid generation, is used here to construct interpolating curves. Good control over the shape of the curves is obtained thanks to the capability of the proposed approach to interpolate not only the data points, but also some directions suitably associated with them.

Notes: Abstract Antennal sensilla were compared in females and males of two sympatric mymarid Hymenoptera, Anaphes victus and A. listronoti which are, respectively, solitary and gregarious parasitoids of eggs of the carrot weevil Listronotus oregonensis (Coleoptera, Curculionidae). Both species are morphologically very similar in the area where they are sympatric. The external morphology of the sensilla was studied using scanning electron microscopy. Female antennae have seven different types of sensilla, morphologically similar in the two species: trichoid sensilla, which are putative mechanosensilla, sensilla chaetica types 1, 3 and 4, which are presumably contact chemosensilla, and sensilla chaetica type 2 and basiconic and placoid sensilla, which are presumed to be olfactory sensilla. The major difference between the two species is the number of sensilla chaetica type 4, of which 6–9 are found on the antennal club in A. victus, while 10–12 are present in A. listronoti. The antennae of the males of both species are similar in morphology and in the number and distribution of their four types of sensilla, i.e. trichoid sensilla, sensilla chaetica type 1 and basiconic and placoid sensilla.

Notes: Abstract  In this study a ground-dwelling (Eublepharis macularius) and a highly specialised climbing (Gekko gecko) lizard were chosen as study objects. The fore- and hindlimbs of two individuals of each species were dissected, and muscle masses, mean fibre lengths, cross-sectional areas and moment arms were determined. Special attention was paid to general muscle architecture (origin, insertion, fibre orientation, etc.) and pennation angles. Using these variables (cross sectional areas and moment arms), maximal moments exertable across the shoulder/hip, elbow/knee and wrist/ankle were calculated for both species. In accordance with the biomechanical predictions related to the preferred locomotor substrate of each species (i.e. level running for E. macularius and climbing for G. gecko), the results of this study indicate that climbers such as G. gecko generally possess powerful retractor muscles crossing the shoulder and hip joints. Additionally, the specialised climber is able to exert higher flexion moments across the elbow, which prevents the animals from falling backwards. However, G. gecko appears to be constrained in its ankle extension capabilities by the presence of the adhesive toe pads. The level-running species, on the other hand, shows a relatively stronger development of the extensor muscles in the lower limbs, allowing these lizards to run in an erect posture. In general, both species show large similarities on a gross morphological level as expected when considering their phylogenetic relatedness. Adaptations to their preferred locomotor substrate only become apparent when considering the functional properties (i.e. joint moments) of the appendicular musculature.

Notes: Pyxicephalus adspersus , is exceptional among living frogs. Embryonic development, larval phase, and metamorphosis can be completed in 17 days at a temperature of 29°C. The metamorphosis only takes 5 days. The present study shows that, despite the unusually short larval phase in P. adspersus, the state of skeletal differentiation reached at the end of metamorphosis is similar to that of other frog species. There is no shift of cranial bone formation postmetamorphosis as could have been expected and is known from other species. The majority of compared species are particularly similar in the sequence of bone formation in the postcranial skeleton. However, there are clear differences among species in the timing of these events relative to the larval growth trajectory, absolute time, and certain developmental markers, such as external limb differentiation. For example, skeletogenesis and externally visible limb differentiation are only loosely integrated. Interspecific comparisons show that, in P. adspersus, the early onset of skeletal ossification is an unusual feature among frogs. Freshly metamorphosed froglets of P. adspersus are already distinct from comparable stages of other species in having strong jaws, fang-like teeth, and a squamosal-maxilla contact. The latter stabilizes the maxillary arcade and the suspensorium and might relate to the ability to catch and swallow very large vigorous prey, such as siblings, shortly after metamorphosis. The presence of a complete set of dermatocranial elements and postmetamorphic ossification of only the sphenethmoid and operculum are considered plesiomorphic features, whereas the much less completely ossified skulls of metamorphosed froglets, particularly in Bufo and Hamptophryne, are likely apo- morphic developmental traits within the Anura.

Notes: Abstract  The phylogenetic position of the Clitellata within the Annelida is still in debate. It is unresolved whether they are a basal group, resembling the stem species of the Annelida, or a highly derived subtaxon, which evolved from a polychaete-like ancestor. A factor often ignored in this discussion is the site of the supraoesophageal ganglion (brain). Its position in the Clitellata, far behind the prostomium, can be regarded as a secondary structural adaptation to a life spent burrowing through relatively firm terrestrial substrates. Such a habit probably led to the complete elimination of prostomial appendages and a marked reduction in size of the prostomium, resulting in a displacement of the brain into following segments. This interpretation of the sequence of events corroborates the view that the Clitellata are a highly derived subtaxon of the primarily marine Annelida. The development of the central nervous system of Enchytraeus crypticus (”Oligochaeta”) was analysed by immunohistochemical methods in combination with confocal laser scanning microscopy. A detailed description of neural structures, including the formation and arrangement of segmental nerves, is given for significant developmental stages. Labelling of neural structures using antibodies against acetylated α-tubulin and serotonin clearly shows that the cerebral ganglion initially develops within the prostomium. In the course of embryonic development it is shifted backwards into segment III. Thus the posterior relocation of the brain, which is inferred as having occurred in the phylogeny of the Clitel- lata, can be demonstrated in the ontogeny of E. crypticus.

Notes: Abstract  Recent reports indicate that neuronal elements develop in early larval stages of some Gastropoda from the Pulmonata and Opisthobranchia prior to the appearance of any ganglia of the future adult central nervous system (CNS). The present study describes similar early neuronal elements in Crepidula fornicata. A posterior FMRFamide-like immunoreactive (LIR) cell with anteriorly projected fibers was observed in the trochophore stage. Additional FMRFamide-LIR and serotonin-LIR cells and fibers were found in the apical organ in the trochophore and early veliger stages. FMRFamide-LIR and serotonin-LIR projections to the velum and foot were also detected at this time. As the veliger developed, peripheral FMRFamide-LIR and later catecholaminergic cells were located in the foot region. Also during this stage, catecholaminergic cells and processes were observed near the mouth. In addition, this study tentatively identified the first serotonin- and FMRFamide-LIR cells and fibers within the developing ganglia of the adult CNS, which appeared in close proximity to the earlier developing elements. These observations are consistent with the hypothesis that, in addition to its presumed role in the control of larval behaviors, the larval nervous system guides the development of the adult CNS. Larvae from the class Bivalvia and other invertebrate phyla also have neuronal elements marked by the presence of FMRFamide, serotonin, and catecholamines, and, therefore, this study may provide additional insights into phylogenetic relationships of the Gastropoda with other representatives of the Mollusca and different invertebrate phyla.

Notes: Abstract  The eyes of different larval stages and juveniles of Atlanta peroni are generally composed of a cornea, a lens and a retina. In juveniles a distinct pigmented shield is visible and an enormous humour is located behind the lens. Larvae have only two sensory cells and the photoreceptors are of the ciliary type. In juveniles a striking feature is the shape of the retina. It is ribbon-shaped and new sensory cells are present which are arranged in three rows. The photoreceptors are of the ciliary type as well. Contrary to the arrangement in larvae, the ciliary plasmalemma in juveniles forms numerous lamellar stacks. In accordance with the sensory cells the stacks are organized in three parallel rows. The lamellae of adjacent stacks within a row overlap each other. The latter unique feature has not yet been found in any other representative of the Heteropoda. These findings demonstrate that (a) the eyes are altered during the development from larvae into juveniles, (b) the larval sensory cells are reduced and replaced by new sensory cells in juveniles and (c) the eyes of juvenile and adult A. peroni are well adapted for their life as visual predators.

Notes: Abstract  Two independent methods of comparison, serial homology and phylogenetic character mapping, are employed to investigate the evolutionary origin of the noctuoid moth (Noctuoidea) ear sensory organ. First, neurobiotin and Janus green B staining techniques are used to describe a novel mesothoracic chordotonal organ in the hawkmoth, Manduca sexta, which is shown to be serially homologous to the noctuoid metathoracic tympanal organ. This chordotonal organ comprises a proximal scolopidial region with three bipolar sensory cells, and a long flexible strand (composed of attachment cells) that connects peripherally to an unspecialized membrane ventral to the axillary cord of the fore-wing. Homology to the tympanal chordotonal organ in the Noctuoidea is proposed from anatomical comparisons of the meso- and metathoracic nerve branches and their corresponding peripheral attachment sites. Second, the general structure (noting sensory cell numbers, gross anatomy, and location of peripheral attachment sites) of both meso- and metathoracic organs is surveyed in 23 species representing seven superfamilies of the Lepidoptera. The structure of the wing-hinge chordotonal organ in both thoracic segments was found to be remarkably conserved in all superfamilies of the Macrolepidoptera examined except the Noctuoidea, where fewer than three cells occur in the metathoracic ear (one cell in representatives of the Notodontidae and two cells in those of other families examined), and at the mesothoracic wing-hinge (two cells) in the Notodontidae only. By mapping cell numbers onto current phylogenies of the Macrolepidoptera, we demonstrate that the three-celled wing-hinge chordotonal organ, believed to be a wing proprioceptor, represents the plesiomorphic state from which the tympanal organ in the Noctuoidea evolved. This ’trend toward simplicity’ in the noctuoid ear contrasts an apparent ’trend toward complexity’ in several other insect hearing organs where atympanate homologues have been studied. The advantages to having fewer rather than more cells in the moth ear, which functions primarily to detect the echolocation calls of bats, is discussed.

Notes: Abstract  To investigate structural differences between propulsory and antigravity muscles, the spatial distribution of slow (type I) and fast (type II) muscle fibres in forelimb muscles of two species of small mammals was studied, Galea musteloides and Tupaia belangeri. Serial sections through complete forelimbs were prepared. Following histochemical fibre typing, the forelimbs were reconstructed three-dimensionally using product design software. Most forelimb muscles of both species showed a homogenous distribution of type I fibres. In the supraspinatus and triceps brachii (capita longum et laterale) muscles, however, a segregation of fibre types into ”fast” superficial areas and ”slow” deep regions was observed. Slow regions contained at least 60% type I fibres and were positioned along intramuscular extensions of the tendons of insertion. The functional implications of fibre type regionalization are discussed. An analysis of intramuscular fibre type distribution during postnatal myogenesis revealed no significant differences in muscle fibre differentiation between altricial and precocial juveniles. Differences in locomotor ability probably arise from heterochronic development of connective tissue components (endo- and perimysium).

Notes: Abstract  The fine structure of spermiogenesis and spermatozoa in three species of the Macrostomorpha was studied, with emphasis on Bradynectes sterreri. Two centrioles appear during the development of sperm cells, at least in B. sterreri and Paromalostomum fusculum. Initially these organelles have a perpendicular position, but later they come to lie in line with each other. In P. fusculum, the differentiation of rootlet structures inserting on both centrioles was found. However, ciliary axonemes do not grow out, either in B. sterreri or in P. fusculum. These two species, and also Haplopharynx rostratus, have aciliated spermatozoa. The mature male gametes of B. sterreri are characterized by a filiform nucleus, numerous mitochondria, dense bodies irregular in shape, membranous lacunae, a pair of electron-dense lateral ledges and two sets of cortical microtubules in addition to a closed ring of microtubules in the posterior segment of the cell. Both lateral ledges do not originate from the centrioles. ’Lateral ledges’ or ’lateral bristles’ were not observed in spermatozoa of H. rostratus and P. fusculum. Such structures cannot be considered autapomorphic for the Macrostomorpha. The known spermatological characteristics contribute to elucidating the interrelationships of the Macrostomorpha. Haplopharynx and Macrostomida are sister groups. Spermatozoa with cortical microtubules separated into two sets are hypothesized as an autapomorphy of the Macrostomida. The two lateral ledges found in spermatozoa of B. sterreri are discussed to correspond to the pair of ’lateral bristles’ known from Macrostomum species, indicating a sister-group relationship of these two taxa. Apparently, the aciliated spermatozoa of Macrostomorpha species originated from biciliated male gametes. Hence, biciliated spermatozoa are not an evolutionary novelty of the Trepaxonemata, but of the Rhabditophora.

Notes: Abstract  Convoluta pulchra is a small worm living in the surface sediment of mud flats where it feeds on diatoms. It is roughly teardrop in shape with a ventral groove in which the mouth sits, and it can move in a variety of ways, readily distorting its body in bending, twisting, and turning motions. Fluorescently labeled probes for filamentous actin revealed the musculature in whole mounts of the worm. In the body wall, the musculature consisted of a grid of circular, longitudinal crossover (that is, with a longitudinal orientation in the anterior half of the body but arcing medially to cross over to the contralateral side of the body behind the level of the mouth), and a few diagonal fibers. Inside the body was a strong, irregular brush of muscles originating at the rostral tip of the body and anchoring laterally and posteriorly along the body wall, and strong dorsoventral muscles flanked the ventral groove. Two fans of muscles in the ventral and dorsal body wall reached posteriorly and laterally; that on the dorsal side originated at junctures of the dorsoventral muscles with the body wall and that on the ventral body wall originated from the mouth. By their positions, certain groups of muscles could be correlated with given movements: the crossover muscles with some turning motions and feeding, and the inner muscles with probing and retraction motions of the rostrum and with a tuck-and-turn motion the worm used to turn itself around. Electron microscopy showed numerous maculae adherentes junctions linking all muscle types and special junctions linking the musculature with the epidermis. The latter myoepidermal junctions were of dimensions larger than those of maculae adherentes and contained an interlaminar material which we believe represents islands of basal matrix comparable to basement membrane.

Notes: Abstract  Adhesion to smooth surfaces by means of thin fluid lipid film was studied on living larvae of 71 species of Lepidoptera by a simple ”light reflection method”. The method made it possible to localize exactly the sites of adhesion and to estimate roughly the film thickness, within a certain range. Furthermore, it revealed the general presence of mobile lipid on the entire insect surface. The observations on living larvae were complemented by comparative structural studies of the adhesive parts with light and scanning electron microscopes on preserved specimens of 161 species. Specialized adhesive devices were found in great diversity on larval legs and prolegs, especially in larvae living in the open air on their food plants. Two main surface types of adhesive cuticle were found: (1) cuticle with a flexible smooth surface and (2) cuticle with very numerous small projections (microtrichia) with spatulate and recurved apices. Both the functional implications of the adhesive cuticular structure and the role of the adhesive fluid as well as the evolution of the adhesive devices are discussed. The adhesive effect is due to ”capillary” or meniscus forces.

Notes: Abstract  A comparative SEM investigation of the transphragma representing the medioanterior margin of the first abdominal tergum in ditrysian Lepidoptera resulted in the establishment of a directed transformation series of gradual modifications. Most remarkably, an additional phragma, for which the term euphragma is proposed, must be assigned to the ground pattern of the Obtectomera. However, this assumption implies that a subsequent loss of the euphragma must be attributed to the ground patterns of the Axiidae, Copromorphoidea, Doidae, Papilionidae and the Hedylidae. On the other hand, a typical euphragma is also observed in the non-obtectomeran superfamily Sesioidea. Similarly, the phylogenetic significance of the presence of a much smaller circular phragma in the Choreutidae is not yet understood. Either the three taxa (Obtectomera, Sesioidea and Choreutidae) constitute a clade, and secondary modifications have obliterated the euphragma on a number of occasions, or the euphragma has been developed independently on more than one occasion. Potential autapomorphies of various subordinate taxa are also discussed.

Notes: Summary The embryo ofOncopeltus fasciatus forms a typical secondary dorsal organ (SDO). It develops after katatrepsis from the contracting serosa, the cells of which decrease in diameter but increase considerably in height. After 66 h, the SDO represents a protrusion of the serosal epithelium above the head and is then reduced to a disc-shaped formation, which sinks into the yolk, where it disintegrates after 80 h. During its typical expression, between 66 and 78 h, the SDO shows a zonal arrangement of its cell organelles. The nucleus, which is located in the basal cell region, has a very irregular outline and includes several nucleoli and globular inclusion bodies. Rough and smooth ER are well developed around the nucleus and suggest the involvement of the organ in protein secretion as well as in lipid metabolism. Electron-lucent vacuoles and electron-dense granules, sometimes enclosed in the vacuoles, accumulate in the apical cell region, and are obviously extruded into the peripheral (extraembryonic) space. The formation of intercellular clefts and delicate cytoplasmic extensions facing the yolk and microvilli facing the periphery evidence a transporting function of the epithelium. Blisters intercalated in extended junctional complexes between apical cell regions point to the transport of solutes. Because of the similarities of the processes observed in the SDO and in Malpighian tubules of larvae, an excretory function of the SDO is suggested. Final products of yolk and embryo are apparently transported to the extraembryonic space, where they accumulate during embryogenesis. Phylogeny, relationship, and function of the different embryonic glands in Arthropoda (primary and secondary DO and pleuropodia) are discussed.

Notes: Summary Biomphalaria (Australorbis) glabrata has a preradular as well as a postradular pocket and a collostyle hood. The odontophore cartilage does not consist of cartilage, but of cells which are characterized by numerous vesicles, mitochondria, and muscle fibres in the periphery; other cells contain large amounts of glycogen. The odontoblasts are characterized by unusually long microvilli which reach into the newly formed radula teeth. The formation of a tooth begins above the posterior odontoblast which has at first only short microvilli. The tooth seems to be raised by the extension of these microvilli. Microfibrils are formed in the electron dense material which is present in the small space between the microvilli; probably these microfibrils contain chitin. Obviously the interlacing of the bundles of microfibrils in a tooth corresponds with the complex arrangement of the long microvilli during formation of the tooth. Finally the microvilli are integrated into the newly formed tooth and radular membrane. Several odontoblasts join to form a single tooth. The radular membrane is secreted mainly or exclusively by the most anterior odontoblast. The cells of the superior epithelium surround the radula teeth. The so-called “secretion cavity” seems to be an artifact. Electron dense material is present between teeth and superior epithelium which is not apposed to but seems to be integrated into the teeth. The cells of the inferior epithelium show considerable secretory activity; the secretions seem to be incorporated into radular teeth and membrane.

Notes: Summary The young recent cassiduloidEchinolampas depressa has a lantern and teeth which are fully developed, but which never function because they disappear completely after metamorphosis. The lantern resembles morphologically that of the clypeastroid family Fibulariidae. The teeth are built-up of tooth elements, which have small primary plates, large lateral plates, and a cluster of prisms, and they are nearly identical to the teeth of fibulariids. In addition, the fine structure of teeth from liassic fossils was analyzed. This was the first investigation ever of the microstructure of fossil echinoid teeth. The examined teeth were well preserved, and proved to have nearly the same structure as the teeth ofEchinolampas. The results of this investigation prove that teeth of cassiduloid-clypeastroid structure were already in existence in the Liassic. Using micro structure as a comparative basis the author distinguishes between echinoid teeth of the “clypeastroid type” (present in Cassiduloida, Clypeastroida, and in all probability in Oligopygoida), and those of the “regular type” (present in all recent regular echinoids and in all probability in Holectypoida). The well-known aulodont, stirodont, etc., types of teeth and lanterns belong to the regular type. Teeth of the regular type are highly complex in structure, and certainly cannot be the result of evolutionary convergence. From the morphological point of view the clypeastroid type is the simpler one, and there is no indication that it is the result of secondary simplification. For this reason the anatomical features of the clypeastroid type of echinoid teeth are considered to be the more primitive. Contrary to the opinion of several authors, this author maintains that echinoids possessing a masticatory apparatus of the clypeastroid type are by no means descendents of stirodont ancestors.

Notes: Summary Numerous short ciliary structures are described in immature spermatozoa of a marine catenulid,Retronectes atypica (Doe and Rieger, 1977). These ciliary structures are associated with spherical bodies consisting of concentric flat vesicles. Since such spherical bodies have been described for several other species of Retronectidae (Sterrer and Rieger, 1974), it is assumed that the multiple ciliary structures may be a characteristic of the whole family. Nuclear morphology and other cytological structures are described for mature and immature stages of spermatogenesis. The finding of these ciliary structures is thought to underline the unique and isolated position of the Catenulida within the Platyhelminthes and the lower worms as a whole.

Notes: Summary The ocellus of a synaptid holothurian,Opheodesoma spectabilis, is composed of sensory and supportive cells and underlain by numerous bundles of tentacular nerve fibers. Pigment cells in the tentacular nerve envelope the ocellus. A sensory cell is divided into three parts: an apical part from which a single cilicum and numerous microvilli arise, a slender middle part, and an enlarged basal part that contains an oval nucleus and gives rise to an axon. The axonemes in the cilia show varying degrees of remodelling. The following changes result from exposure to light: the microvilli become shorter and irregularly arranged; plasmalemmal invaginations engulf the microvilli; coated vesicles of varying appearances and membranous fragments become abundant; microtubules are less evident in the apical part; and small flat vesicles appear along the plasma membrane in the middle part. The evolution of photosensory cells and membrane turnover are discussed.

Notes: Summary 1. Studying speciation processes ofGyratrix hermaphroditus 16 populations from 15 little ponds in Lower Saxonia were examined. 2. Basically two types of life-cycles are recognized in populations ofGyratrix. Polyvoltine cycles from April to October and sometimes over the winter months occurred in eurytherm populations. Dormance periods are facultative. The life-cycles of the psychrophileous populations are univoltine from February or March to May or June. A period of 9 months or more is survived in the egg capsules by a diapause. 3. In morphology the form and largeness of the egg capsules and the male cuticular-organs is significant different in small, medium-size and large specimens. The chromosome-set of a medium-size population is tetraploid with 2n=8,n=4. Numbers of chromosomes of all other populations are 2n=4,n=1. 4. Reproductive isolation exists between five populations. ThereforeGyratrix is considered as a group of closely related species forming at least five sibling species. The range of two populations is unknown. The biota of the sibling species are isolated ponds or ponds in the neighbourhood one to another. In one case two species are living sympatric in the same pond. 5. The origin of the speciation processes are refered to autopolyploidy, ecogeographical differenciation and change of chromosome structure. Primarily the reproductive isolation is caused by a sexual substance, inhibiting copulation. It is different in all populations. 6. The supposition pointing out further sibling species from marine, brackish and limnetic biota renounced us to give a taxonomic term. The species groupGyratrix hermaphroditus is provisionally carried on under this name.

Notes: Summary The ultrastructure of the epithelium on the oral surface of the tentacles ofOwenia fusiformis has been studied by light and electron microscopy. Unspecialized monociliated cells are the dominant cell type of the epithelium; however, biciliated epidermal cells, monociliated mucous cells and non-ciliated cells are also present. In all of the ciliated cells each cilium is provided with a diplosomal basal body and two striated rootlets. The cytological features of this unspecialized epithelium strongly resemble those of similar epithelia in the Phoronida, Brachiopoda and Hemichordata. So far,O. fusiformis is the only polychaete known to possess an unspecialized monociliated epidermis. Other characters ofOwenia are also mentioned. The relationship between the nervous system and the epidermal cells on the tentacles is examined. It is proposed thatOwenia should assume an important role in discussions of the phylogeny of the Polychaeta.

Notes: Summary The sound producing organ ofTrichopsis vittatus consists of a very enlarged part of the M. adducor superficialis. It is found at the inside of the cleithrum, which is attached to the fourth and fifth pectoral fin ray by two tendons, thickened to elastic pads. These pads are situated above an elevation formed by the base of the second and third fin rays. In experiments it is demonstrated how the double-pulsed tone bursts are generated by the pads snapping over this elevation during the contraction of the sonic muscle. If the sonic muscle is cut, the sound production ceases. If one of the two tendons is cut, the former double-pulsed tone burst turns into a single-pulsed burst.

Notes: Summary The paired copulatory stylets of the hermaphroditicMicrophthalmus cf.listensis are hard cone-shaped tubes with a syringe-like distal opening and a cuff-like lower edge and surround the external openings of the two ejaculatory ducts. They each lie in a deeply invaginated epidermal fold and are attached basally to an elongated muscle bulb, which is composed of a number of disc-like muscle cells. A prominent gland is situated behind the stylets. Transfer of sperm into the partner occurs probably by mechanical hypodermal injection. Hereby, the epidermal folds are protruded as small sacks, pulling out the stylets. The development of the entire male genital apparatus occurs in autumn when the animals have about 16 setigerous segments. During this differentiation, two elongated papillae arise. They consist of various well defined cells, some of which border a central ciliated lumen. The stylet tubes arise by transformation of the at first normal cuticle of these papillae into a hard electron-dense wall.

Notes: Summary The structure of the eyespots of the free-swimming larva ofPolystoma integerrimum (Monogenea, Polystomatidae) was studied by electron microscopy. Each eyespot is rhabdomeric in type, with one cup-shaped supportive cell and one sensory cell. The supportive cell is characterized by concentric rows of platelets, separated by 120 nm. This entirely new structure in a platyhelminth acts like a concave mirror of a telescope in concentrating the light. Moreover, at each interface of lamellae of platelets, light is amplified. InPolystoma, the light concentration occurs by reflection whereas it occurs by refraction in all other platyhelminths studied up to now. Among the monogenean Trematodes, all the Polystomatidae appear to present this reflecting system.

Notes: Summary The structure of the gonopodium ofHeterandria formosa was studied by light- and electron microscopy (scanning and transmission EM). In adults the number of the analis fin rays varies between 8 and 11. The anterior part of the fin which is extremely reduced in size, contains rays I and II, the median part modified for use in copulation is stabilized by rays III to V, whereas the posterior part revealing ordinary size, contains rays VI to VIII/IX/X/XI. Ray III is the main supporting element of the gonopodium. The anterior ramus of ray IV bears proximal serrae and is elongated, thus forming a terminal hook of genus specifity. InHeterandria formosa the suspensorium consists of 4 gonapophyses, 9 interhemal spines and a number of baseosts. The peripheral part of the dermis of the gonopodium is made up by a multilayered epithelium. Most of the epithelial cells are extremely toothed with numerous desmosomes. Microridges of the outer cells form a meandrian surface pattern. There are few free nerve endings within the epithelium. A basement membrane of varying thickness separates the epithelium from an underlying thin layer of connective tissue which surrounds the central bone tissues of the gonopodium. Blood vessels and nerve fiber bundles are embedded in the bone tissue. The endothelial cells of the afferent capillaries form thin lamellae which are overlapped in part. The contacts of the endothelial cells are made up by gap or tight junctions. The functional morphology of the gonopodium is discussed corresponding to the anatomical and ultrastructural findings.

Notes: Summary Ciliary gliding is a type of locomotion in which an animal moves on a secreted layer of mucus, propelled by the beating of cilia. It is characteristic of small, soft-bodied invertebrates and has received little attention. However, the interactions between cilia and mucous secretions involved in ciliary gliding are similar to, if not the same as, those in other muco-ciliary systems such as the mammalian lung or the ctenidia of bivalves. In this paper, the ultrastructure of the ciliated and mucous secreting cells on the locomotor sole of two archiannelids (Protodrilus sp. andNerilla antennata) and two turbellarians (Polychoerus carmelensis andMonocelis cincta) is described and discussed in terms of a proposed mechanism of ciliary gliding.

Notes: Summary Rhabdites are rod-shaped secretory products characteristic of the Turbellaria but also found in nemerteans, gastrotrichs and annelids. Their functions are poorly understood. The structure, synthesis and secretion of rhabdites were studied in one archiannelid (Protodrilus sp.), and three turbellarians (Alloioplana californica, Polycladida;Monocelis cincta, Alloeocoela;Polychoerus carmelensis, Acoela). InAlloioplana, Monocelis andPolychoerus the rhabdites are the only, or most common, secretory product released on the ventral locomotor sole and therefore they are thought to form the viscous mucus used in locomotion by ciliary gliding. InProtodrilus, rhabdites are released along the ventrolateral margin of the worm and are secreted only when the worm tries to move by ciliary gliding against strong water currents. It is proposed that the principal function of rhabdites in the worms studied, is adhesion.

Notes: Summary Pigmented spots have been implicated as potential photoreceptors in many bryozoan larvae which display phototactic behavior. Larvae ofScrupocellaria bertholetti, initially photopositive on release from the brood chambers, have a pair of identical posterolateral pigmented spots and a third morphologically different spot in the anteromedian line. The presumed photoreceptoral organelle in each is composed of numerous unmodified cilia which have the typical 9+2 arrangement of microtubules with electron-dense arms extending from thea-microtubule of each peripheral pair. The posterolateral pigmented spot is composed of two modified coronal cells and a basal sensory cell. Cilia arising from the apical part of this basal cell are aligned vertically. Densely packed pigment vesicles in the three cells form a shield that restricts light entry to one direction. The anteromedian pigmented spot is composed of four cells, two lateral and two posterior. Cilia of the opposing lateral cells are horizontally aligned, whereas cilia of the posterior cells are vertical and curve outward from the oral margin of the pigmented spot. Pigment vesicles are present in all four cells to form a complete shield. Extensions of the larval nervous system are in direct contact with the four cells of the anteromedian spot and the basal cells of the posterolateral spots. The posterolateral pigmented spots share structural and topological similarities with the pigmented spots ofBugula neritina, the only other supposed photoreceptors in lophophorates which have been studied at the ultrastructural level. It is not yet possible to homologize these potential photoreceptors with those of other groups.

Notes: Summary An investigation of the neurosecretory cells of three intertidal species of nemerteans,Procephalothrix spiralis (Coe, 1930) (Palaeonemertini),Lineus socialis (Leidy, 1855) (Heteronemertini) andAmphiporus lactifloreus (Johnston, 1828) (Hoplonemertini) was performed. Cell types are described and their distribution and relative abundance in the central nervous system reported. Neurosecretory cells were examined for diel activity and a relationship with sexual state. A change in the cytology of the neurosecretory cells was only noted with respect to the sexual state of the animal.

Notes: Summary In the anterior head region ofMacrobiotus hufelandi four sensory regions were identified, and a detailed description of their fine structure follows. According to their position in the head region the sensory regions were called; I. anterio-lateral sensory field (ALSF), II. circum-oral sensory field (COSF), III. sub-oral sensory region (SOSR), and IV. pharyngeal organ (PO). The ALSF is innervated by three pairs of fiber bundles made up of dendrites. These bundles originate in the brain, pass foreward laterally, and widen, brushlike, under the epidermis. The COSF circumscribes the whole mouth opening. Under the specialized cuticle of the COSF, dendrites of three sensory cell types (type 1–3) terminate. The SOSR surrounds the anterior cuticular ring of the mouth cavity. It is also innervated by dendrites of three sensory cell types (type 1–3). The dendrites are arranged arround the mouth cavity in ten groups, each group being composed of three. Each dendritic triplet contains the sensory cell types 1–3. The PO is represented by four cuticular pockets. These are located at the transition between mouth cavity and mouth tube and innervated by 3–5 dendrites each. The cuticular pockets enclose considerable receptor lymph cavities which communicate with the lumen of the anterior foregut over multiple pores. With regard to the possible functions of the four sensory regions, the ALSF is discussed as a mechanoreceptive organ. The type 1 sensory cells in the COSF are suggested to be chemoreceptive and the type 2 sensory cells to serve as me-chanoreceptors in the COSF. For the sensory cells of type 1 in the SOSR, a movement of the anterior cuticular ring of the mouth cavity is considered to be adequate (mechanical) stimulus. The PO is thought to be a chemoreceptive sense organ.

Notes: Summary An enveloping sheath of the central nervous system and nerves of chilopods, hitherto called “outer neural lamella” actually consists of mostly myelinized cells supporting the neural lamella. Its fine structure was examinated in some geophilomorphs. Ganglia, connectives and thick trunk-nerves are enclosed by this myeline sheath totally. The myeline sheath is always formed by several cells; the myelinized parts of them are arranged spirally. The number of their “windings” and therefore also the number of the cells taking part in their construction depend on the region and its diameter: ganglia are distinguished by few “windings” — even missing sporadically —, connectives and nerves are distinguished by numerous ones. In connectives and nerves the number of “windings” is correlated with the thickness of the former. Corresponding to the construction of the myeline sheath by several cells, the pericarya of these cells are located above all within the “windings”. The nuclei are lens-shaped; the cytoplasm contains many spherical mitochondria, cytosomes of various form and density, prevailingly rough endoplasmic reticulum and Golgi fields and free ribosomes near the nucleus. Within the myelinized parts there is no cytoplasm, transparent dilatations between the membranes may be artificial. Cell membranes are outwardly supported by a glycocalyx. Between neighbouring glycocalices there is a haemocoele-cleft of variable width in which haemocytes are not seldom found squeezed in. Adjoining cells of the sheath overlap with their myelinized parts over a large area. Their glycocalyx disappeared and cell contacts have formed, recognizable in sections as septated desmosomes. The meaning of this myeline sheath is discussed.

Notes: Summary The following study should clear up the structures of the H-shaped profile found in the hairs of some shrews and show if it has a taxonomic signification. Therefore we studied the concerned hair structures by scanning electron microscopy in 8 genera. The special hair-shape, which is confined to the terminal segment of guard hairs, is found in the species of the following genera:Sorex, Neomys, Blarina andCryptotis, all members of the subfamily Soricinae. All the examined members of the subfamily Crocidurinae, i.e.Crocidura, Praesorex, Suncus andSylvisorex show a simple hair shape. The H-shaped hair characterizes the Soricinae as a monophyletic unity. Yet, the morphological criteria of hair complete the osteological criteria of Repenning (1967) an plead for the validitiy of the often refuted subfamilies.

Notes: Summary Mating behaviour and sperm transfer inTh. amazonicus andT. crucifer are similar to that ofMastigoproctus. During the short courtship the male graps one (Thelyphonellus) or both (Typopeltis) antenniform legs of the female and holds their tips between his chelicerae. Then he turns until both animals face the same direction, and the female embraces the male's opisthosoma from below and behind. After the “mating parade”, the male deposits a spermatophore and pulls the female over it. The female picks up two sperm packages from the spermatophore and releases the male's opisthosoma. The male now turns, embraces the female's opisthosoma from above and with his palpal chelae pushes the sperm packages into the female's gonopore. Thereafter, the sperm packages are emptied by different movements.Thelyphonellus usually starts a second mating dance and sperm transfer behaviour immediately after the first one has been finished. The sperm packages ofThelyphonellus are elongate and similar to those ofMastigoproctus. Their tips are partly protected by a conductor like structure. After having been pushed into the female's gonopore only the blunt ends of the sperm packages protrude. These are pulled to the sides of the genital slit and pushed toward the midline again by the male again and again, and thereby the sperm packages are partly emptied. The male manipulates the blunt ends of the sperm packages with the tips of the movable fingers of his palpal chelae which are help open. InTypopeltis, the sperm packages are not elongate. They are pushed completely into the female's gonopore. Thereafter the male strongly presses onto the female's genital operculum and thus empties the sperm packages. During this process the male's palpal chelae are closed and, together with the modified patellar apophysis, form a strong pressing instrument. Sperm transfer seems to be more specialized and effective inTypopeltis than inThelyphonellus andMastigoproctus,

Notes: Summary Ultrathin cross sections of the tracheid wall in black spruce and silver fir have been examined at high resolution by scanning transmission electron microscopy (STEM) and by conventional transmission electron microscopy (TEM). For both softwoods, lamellation of the S2 layer was evident but the lamellae were seen more clearly in the STEM photomicrographs. The interlamellar distance was 7.1 nm in the case of spruce and 8.4 nm for silver fir.

Notes: Summary Increased utilization of eastern spruce and balsam fir has led to a need for a quick method of separating these woods in a mill situation. One such method might be the use of a chemical indicator. A test of various classes of chemical agents applied at different seasons of the year showed that a pH indicator might be suitable for achieving a separation. The most suitable indicator was tested on samples from different geographic locations and at three highproduction stud mills. Additional tests were conducted to explore such variables as moisture content and surface condition of the wood, type of solvent, concentration and temperature. The most suitable indicator found was bromophenol blue at a concentration of 0.10 percent in 95 percent ethanol. When applied to green wood which had been allowed to dry for a few minutes to a few hours, this indicator produced various shades of orange, yellow, green or blue with spruce and a dark blue or blue-violet with fir. With an understanding of the variables that affect the reaction, it is felt that bromophenol blue can be used for the separation of eastern spruce and balsam fir on a commercial basis.

Notes: Summary There is a positive correlation between the percentage of compression wood and specific gravity in Pinus wallichiana. Where compression wood is present a definite increase in specific gravity occurs in an annual ring, but the influence of compression wood on specific gravity is only local. The first-formed earlywood portion of the ring is the most suitable sampling point for a comparison of specific gravity between rings of the same or different trees.

Notes: Summary The dynamic moduli and logarithmic decrement of Rimu (Dacrydium cupressinum) were measured along the grain and perpendicular to it in the frequency range 45–85 kHz using a Marx regenerative oscillator system. The moduli and decrement were observed to exhibit strong dispersions between-20°C and-80°C, the actual temperature being dependent on measurement frequency and moisture content of the sample. The activation enthalpy of the dispersion mechanism varied from 3.9 kcal/mole at moisture contents in excess of 7 % to 6 kcal/mole at lower (1%) moisture content. Impregnation of the wood with solvents produced dispersion effects different from those associated with water impregnation. It is postulated that this mechanical dispersion observed in moisture-bearing wood results from the motion of the adsorbed water molecules.

Notes: Summary Compression wood in the ancient Ginkgo biloba differs from that in most of the younger gymnosperms in the more angular outline of its tracheids, their thinner walls, and their lack of helical cavities. Both normal and compression woods of Ginkgo contain two types of tracheids, one wide, with a thin wall, and another, narrow, with a thicker wall. In all other respects the compression wood tracheids in Ginkgo are ultrastructurally similar to those in other gymnosperms. Helical cavities probably developed relatively late in the evolution of compression wood, since they are missing not only in Ginkgo but also in the Taxales and the Araucariaceae. The occurrence of compression wood in Ginkgo biloba indicates that this tissue probably has existed since the Devonean period. Very likely, the arborescent habit of the gymnosperms has always been dependent on their ability to form compression wood.

Notes: Summary The different approaches to the use of steady-state gas flow data in the prediction of the steady-state axial permeability of wood to liquids are reviewed. Since these may be shown to have certain theoretical shortcomings, a new predictive method based on a computer analysis is presented. This and previous methods are tested experimentally; apparently, none can be relied upon to predict the liquid permeability accurately. However, it is clear that the true liquid permeability is not measured; the reasons for this are uncertain. Until this difficulty is resolved, the precision of predictive methods cannot be accurately assessed.

Notes: Abstract After enzymic hydrolysis of polysaccharides in milled wood or pulp the unhydrolysed lignin residue becomes soluble in certain polar solvents. Extensive disintegration of the wood is necessary to obtain a sufficient accessibility toward the enzyme. For milling a porcelain rotary ball mill is recommended. A relationship has been found between the milling energy, which is proportional to the size of the mill, the milling time, and the yield of ball-milled wood lignin (BMWL). Enzymatically isolated lignin (EIL) requires a critical milling time which is shorter than that for obtaining maximum yields of BMWL. A procedure for isolation of the total lignin content from wood and pulps in the form of three fractions has been developed, giving a water soluble, low molecular carbohydrate-lignin complex by water extraction of ball-milled wood, a BMWL-carbohydrate complex by subsequent extraction with dioxane, and a EIL-carbohydrate complex by dioxane extraction of the residue after enzymic hydrolysis.

Notes: Summary Wood radiation densitometry started with the β-ray method but was largely developed with the X-ray method. The density components obtained have been successfully used directly for anatomical, physiological and technological studies. But they also serve as dependent variables to determine the effects of heridity, fertilization, growth rate, entomological defoliation, irrigation, industrial smokes, green pruning, phenology or climatic factors on wood structure or quality and as explanatory variables to elucidate mechanical strength, windbreaks on living trees or sawteeth performances.

Notes: Summary After a β-D-1,3-linked glucan had been isolated from compression wood, identified, and named ‘laricinan’, other researchers suggested that it occupied the helical cavities in the S2 layer of those tracheids. They postulated that the glucan was responsible for the capacity of compression wood to generate the large forces associated with reorientation of displaced stems and branches, and also caused its severe shrinkage with drying. Analyses herein indicate that it is improbable that such a glucan could be the primary factor responsible for those characteristics of compression wood. An alternative significance is proposed, namely that its presence strengthens the already well-supported deduction that the helical cavities have a schizogenous origin.

Notes: Summary A mathematical model has been derived for the prediction of the resistance to viscous liquid flow generated by tracheid lumina and various parts of the bordered pit structure. The model also takes into account changes in pit geometry occurring as the pit membrane deflects when a pressure differential is applied across it. Methods for checking whether flow is truly viscous are presented. Data calculated for Pinus sylvestris suggest that the permeability of earlywood differs markedly from that of latewood; that in latewood the pit apertures contribute significantly to the total resistance to flow; and that kinetic energy corrections to the Poiseuille viscous flow equation may be of some importance at high flow rates.

Notes: Summary The longitudinal tracheids in compression wood of Taxus baccata contain helical thickenings but no helical cavities. The thickenings are as frequent and well developed and have the same ropelike appearance as in normal wood of this species. They are an integral part of the S3 in normal and of the S2 in compression wood and have the same orientation as the innermost microfibrils in these layers. Except for the absence of cavities and presence of thickenings, compression wood tracheids of Taxus baccata possess all the anatomical features typical of such cells, including a rounded outline, intercellular spaces, a thick S1 layer, a highly lignified S2 (L) layer, and no S3 layer. Pronounced compression wood of Pseudotsuga menziesii contains helical cavities but no helical thickenings. Thickenings and cavities seem to be mutually exclusive in Pseudotsuga and Taxus.

Notes: Summary Mathematical models for the polar and dispersion force contribution to the total surface free energy of a solid are reviewed. Experimentally, the geometric-mean and harmonic-mean models are compared for the surface of Douglas-fir wood. Data for both models compare favourably with results from the literature for other man-made and naturally occurring polymeric surfaces. Arguments are offered favoring the use of the harmonic-mean model for characterizing the surface of wood.

Notes: Summary By starting with simple concepts of the molecular structure and building up through the various levels of organisation in the wood cell wall it is possible to construct a model that simultaneously predicts the variation with moisture content change of both the longitudinal Young's modulus and longitudinal shrinkage of wood. To do this it is first necessary to define the stiffness and swelling characteristics of the lignin, hemicellulose and cellulose constituents of the wood as moisture content changes. It is suggested here that it is the bound fraction of the sorbed water that is responsible for the changes in swelling stress as well as for change in stiffness in the lignin and hemicellulose. The magnitudes of the stiffness of each of the constituents appear to be quite closely circumscribed by experimental values for longitudinal Young's modulus and shrinkage of wood and it is apparent that the stiffness characteristics of the in situ constituents are compatible with available experimental evidence for extracted lignin and hemicellulose and for native cellulose.

Notes: Summary Cavity formation in the S2 layer of the secondary cell wall by soft rot fungi is initiated following the establishment of a T-branch by the extension growth of a proboscis hypha. This growth is inhibited after a time and lateral dissolution of the cell wall takes place to form a cavity and enlarge the hypha within it until cavity and hypha are large enough or mature enough to overcome the inhibition to extension growth and a new proboscis hypha is formed and the process repeated. The pointed ends and restrictions to the cavities are brought about by the inhibition of enzyme activity at the ends of the proboscis hypha and the possible deposition of inhibitory material along the pointed ends of the cavity formed.

Notes: Abstract Starting with simple concepts of the molecular structure and models of the stiffness and swelling behaviour of lignin, hemi-cellulose and cellulose and building up through the various levels of organisation in the wood cell wall a model has been constructed that simultaneously predicts the variation with moisture content change of both the longitudinal Young's modulus and longitudinal shrinkage of wood. The model closely predicts both longitudinal shrinkage and Young's modulus as they vary with the moisture content of the wood. The model also takes into account structural variations in the form of changes in cell wall layer thicknesses and mean cellulose microfibril orientation.

Notes: Summary Wood samples that had been ball-milled and extracted with dioxane under various conditions were observed in the scanning electron microscope. Ball milling causes not only a reduction in size of the cells and cell walls but also an internal disruption of the particles. The intensity of milling has a larger influence on the particle size than a prolongation of the milling time. A direct relation was established between particle size and the previously determined yield of purified milled wood lignin.

Notes: Summary The Young's modulus of hemicellulose extracted from Pinus radiata wood has been measured by an indentation method. Values obtained for the modulus varied by almost three orders of magnitude, from 8.0×109 Pa in nearly dry hemicellulose to 1.0×107 Pa in nearly saturated hemicellulose. The very low value of the modulus at high moisture contents has some interesting implications for models of the mechanical behaviour of the wood cell wall.

Notes: Abstract The thermal decomposition of wood wastes obtained from jack pine has been studied in both oxidising and inert atmospheres using thermogravimetric techniques supported by gaseous and residue product analysis. The effects of selected sequences of chemical additives on the reaction rate parameters of both native and extracted bark samples have also been examined. The maximum rate of wood waste pyrolysis is believed to be related to the rapid decomposition of the cellulose constituent, which occurs at around 350°C in nitrogen. In air, this value is shifted to around 300°C and may be explained by the intervention of exothermic reactions involving other wood constituents present in the complex wood matrix. The trend shown in the analytical results for the various wood waste residues was similar to that established by previous workers for the pyrolysis of coalification products on the basis of H/C and O/C ratios which proceed towards the carbonisation and oxidation poles, respectively, for residues obtained from heating in inert and oxidising atmospheres. Isothermal weight-change data were found to fit model kinetic expressions which indicate that the pyrolysis process may be transport-controlled.

Notes: Abstract The helical winding direction of microfibrils in the S2 wall layer in the tracheids, fibres and vessel members of over 250 woody species, both indigenous and exotic, growing in New Zealand has been determined. A Z helix was observed in all the tracheids, fibres and narrower vessel members. The orientation in the wider vessel members could not always be determined with any certainty.

Notes: Summary Fine structure of cellulose microfibrils in poplar (Populus euramericana) gelatious layer and Valonia cell walls was observed in the electron microscope by using disintegration and ultrathin section techniques with various electron stains. Staining of the gelatinous layer in poplar showed that the microfibrils had a paracrystalline region surrounding a crystalline core, but such a region was negligible in Valonia. From the facts that kinks and shortened microfibrils were observed after mechanical and hydrolysis treatments, respectively, and that the microfibrils were unaffected by negative staining, it was concluded that the microfibril core is uniformly crystalline in the longitudinal direction although there may be some crystalline dislocations.

Notes: Summary Experimental data from a series of experiments indicate that the existence of compression damage in timber has a pronounced effect on its toughness, considerably less effect on its tensile strength, and almost no effect on its bending strength. Whereas the toughness of dry timber was reduced by up to 40 per cent at high levels of precompression, toughness of green timber actually increased by up to 37 per cent. The reduction in tensile strength was greater for individual cells and thin sections than for solid timber. The results are discussed in terms of slip plane development and behaviour, and the practical significance of compression damage is emphasised.

Notes: Summary There are, on the average, about 300 fibers or tracheids per centimeter in both the tangential and radial directions in cross sections of softwoods when the counts are made over complete annual rings with the extremes varying from about 200 fibers per centimeter for redwood to about 400 fibers per centimeter for Alaska yellow cedar. Fiber widths, including half of surrounding middle lamella, range from about 50 μm for redwood to 25μm for Alaska yellow cedar, averaging about 33 μm. Average lumen widths vary but slightly with changes in the specific gravity of the wood whereas the double cell wall thickness varies directly with the specific gravity. Effects of pulping to different pulp yields on the fiber dimensions are calculated with the use of two newly developed equations. The theoretical thickness of completely collapsed pulp fibers is equal to their double cell wall thickness. Complete collapse rarely if ever occurs as it requires double fractures of the cell wall. In practice, collapse of fibers is incomplete so their thickness is usually two or more times the theoretical minimum.

Notes: Summary Following a brief review of the main theories of microfibrillar orientation in plant cell walls, several ideas on orientation are proposed which may assist in explaining crossed polylamellate wall structure and the associated reversal of microfibrillar spiral. It is envisaged that microfibrils are synthesized by particles (enzyme granules) moving within, and parallel to, the plane of the plasmalemma; microfibrils are suggested to be deposited on the plasmalemma surface in the wake of the moving particle. Particle movement is postulated to be predetermined in a manner such that the direction of movement within the plane of the membrane basically is straight and undiverted and, as such, describes a geodesic line. A consequence of such movement is that when a particle encounters a cell tip, a change, usually a reversal, in the direction of spiral, and thus of microfibrillar orientation, is generally the result. The precise nature and degree of change in orientation depends on the form of the cell, the shape of the cell tip, and also the initial angle of particle movement with respect to the cell axis. In further postulating the unified movement for many particles the concept of slow viscous flow is considered. The theories presented are discussed with respect to their limitations and to their applicability to specific cell types.

Notes: Abstract Aerodynamic data on the axial velocity and turbulence development of free slot jets is presented. Jets varying from 0.0635 to 0.375 inches (1.59 to 9.53 mm) in width and with air velocities between 2,000 and 10,000 ft/min (10.2 to 50.8 m/sec) were examined. This study was the first phase of a research program aimed at developing empirical data describing impinging slot jet heat transfer commonly used in veneer drying.

Notes: Summary Eucalyptus gomphocephala A.DC seedlings grown horizontally for 103 days had less terminal shoot elongation and higher internal and emanated ethylene levels in the basal portion of the stem than seedlings grown vertically under otherwise identical conditions. Horizontal seedlings had greater radial growth in the upper stem half than in the lower half of the basal portion of the stem. Upper halves contained 60–80 percent tension wood by volume, lower halves 0–10 percent tension wood. Radial growth in vertical seedlings was symmetrical, and they contained negligible tension wood. Upper halves of the basal portion of the stem of horizontal seedlings had greater amounts of internal and emanated ethylene than lower halves and vertical seedling halves. Ethylene differences between random halves of vertical seedlings were smaller than differences between upper and lower halves of horizontal seedlings. The data suggest an association between increased ethylene levels and tension wood formation.

Notes: Abstract  Megarhyssa atrata (Pimplinae) is the largest species known amongst Hymenoptera. In its natural habitat, North America, it is a strict parasito¨ıd of Tremex columba (Hymenoptera, Symphyta, Siricidae). The para- site infests xylophagous host larvae buried in wood. The present work describes the complex movements of the ovipositor during oviposition and its flexibility ensuring the positioning of the stylus at the site of boring. These movements are made possible by the unfolding of the intersegmentary membranes (equipped with a secretory internal surface) and by the full rotation of abdominal segments 8 and 9. During this rotation, the stylus of the ovipositor pushes and extends the membranes completely which, as a result, form a translucent disc measuring 2 cm in diameter. The entry of the stylus into wood is helped by another secretion produced at the tip of the valvulae. This lytic secretion destroys wood fibers. With this set of adaptations, the hymenopteran can bore into a thickness of hard wood and reach its host larvae at a depth of 14 cm.

Notes: Abstract  The Malpighian tubules of Drosophila hydei and D. melanogaster larvae are composed of two types of cell, principal cells and stellate cells. In the anterior larval Malpighian tubules approximately 26% (D. hydei) and 18% (D. melanogaster), respectively, of all cells are stellate cells. In the larvae of D. melanogaster, the stellate cells are fenestrated and the hemolymph space and tubule lumen are separated only by the basal lamina. Injection of dyes into the hemolymph did not indicate any facilitated transfer of substances through the fenestrated cells. The principal cells of the distal segment are carbonic anhydrase positive indicating transport activity, whereas the stellate cells lack this enzyme. In the stellate cells of the transitional segment, the sodium content is strikingly high in comparison to the neighbouring principal cells and lumen where no sodium was detected. This finding indicates that stellate cells reabsorb sodium as supposed earlier in 1969 by Berridge and Oschman (Tissue Cell 1:247–272).

Notes: Summary The ultrastructure of the thread-like hairs (sensilla) on the tibia of the front leg ofAcheta domesticus (Gryllidae) Saltatoria was examined by serial sectioning. The presence of a tubular body indicates that these sensilla are mechanosensitive; electrophysiological measurements also confirmed this. The opposing forces on the articulating apparatus of single hairs and the sensitivity of the single receptor cell were measured after deflection of the hair in different directions. The articulating apparatus is characterized by three cuticular elements: a joint membrane, suspension fibers, and a socket septum. These elements form the basis for a structural bilateral symmetry along whose plane of symmetry the direction line of both the minimum receptor sensitivity and the minimum opposing forces lie. The tubular body embedded in the tip of the socket septum is attached to the base of the hair shaft. The hair provides the leverage for displacing the tubular body and the socket septum limits the extent to which it may be laterally displaced.

Notes: Summary Arteriovenous anastomoses (AVAs) in the afferent region of trout gill filaments originate from two small filament arteries (Fromm's arteries), which parallel the main afferent filament vessel on either side. As in the efferent filament arteries the origin of AVAs is bordered by specialized endothelial cells. Fromm's arteries originate from efferent filament or branchial arteries. A few extremely narrow connections between the afferent filament artery and Fromm's arteries (= afferent shunts) do exist in some gill filaments. Nevertheless, the AVAs in the afferent filament region carry mainly arterialized blood, or blood plasma, to the central venous sinus of the filament.

Notes: Summary Shape and fine structure of the aesthetes located in the uppermost calcareous layer of the shell plates (tegmentum) ofChiton marmoratus L. were demonstrated. Special interest was given to the intrapigmental eye which is laterally inserted in the aesthete body. It consists of a calcareous lens derived from the tegmentum, sensory cells with long microvilli at their distal end forming a rhabdomere, and a pigment cup. The shell eye of the Placophora was compared with the eyes of other invertebrates. We suppose that the intrapigmental eye is derived from a primitive photoreceptor like that we have described of the aesthete body below the macraesthete ofLepidochitona cinerea (L.). The macraesthete probably has no photoreceptor function.

Notes: Summary Embryonic development of holoblastic Penaeidae to a free-swimming nauplius stage is completed within 12h overnight. Difficulty of obtaining material accounts for the lack of a previous investigation ofPenaeus. Development is not influenced by yolk and appears to be very primitive and clarifies some fundamental principles of arthropod development. A comprehensive morphogenetic-ontological comparison of patterns of development in arthropods becomes possible, including phylogenetic considerations. Cleavage is total without early blastomere-inequality and there are no signs of spiral cleavage. The 16-cell-stage consists of equal blastomeres. During the cleavage to this stage polarity of the embryo can be recognized for the first time by the retarded division of a blastomere which marks the vegetal pole. This is due to a graded retardation of cleavage along the animal-vegetal axis. The result of the 5th cleavage is a 30-cell-blastula—two voluminous cells with retarded division mark the vegetal pole. During the 6th cleavage the vegetal pole looses its spherical shape and gets more and more flattened, both the voluminous undivided cells (Mesendoderm) invaginate. The blastoporal aperture, situated in the sagittal axis is surrounded by 8 division-delayed cells, which get displaced as prospective nauplius-mesoderm into the gastrulation cavity as gastrulation advances. They form the inner wall of the invagination gastrula. The occurence of a classic invagination-gastrula can be regarded as an ancestral attribute in the sense of a recapitulation of a phylogenetic stage. Mesendoderm (the first two blastomeres which invaginate at the vegetal pole) differentiates by two divisions at the bottom of the invagination-cavity into: five yolk endoderm cells, a primordial endoderm cell, a primordial mesoderm cell and the primordial germ cell. The position of these elements is preserved in the succeeding development-stages of the embryo. The division delayed primordial cells are displaced in the direction of the blastopore in consequence of the increase of yolk-endoderm cells constituting a pyramide-like projection into the gastrocoel-cavity. The blastopore survives during early development and allows a good orientation of the embryo to be made. The outlines of the naupliar appendages are folded out in a lateral position. Nauplius mesoderm follows the outgrowths as prospective appendage musculature. At the animal pole neuro-ectoderm (presumptive naupliar nervous system) is displaced into the interior in a second invagination in the sagittal axis, followed by immediate closure of the cleft. The undivided primordial cells of the mesendoderm pyramid are displaced with the enlargement of the yolk endoderm without changing their position in the immediate vicinity of the blastopore. Situated in the outgrowing postmandibular rudiment the primordial cells start their division activity which can be observed very clearly. The primordial endoderm cell constitutes the beginning of the midgutrudiment epithelium. The primordial mesoderm cell divides into the initials of the teloblastic mesoderm. The characteristically situated primordial germ cell divides maintaining the same position in the embryo. In the ventral ectoderm of the postmandibular rudiment the formation of the ectodermal growth zone can be observed. It corresponds to the ectoteloblastic region of the meroblastic arthropods and is arranged symmetrically around the mediocentral ectoderm cell. Before hatching, the nauplius-body is bent ventrally in the surrounding egg membrane with the naupliar appendages projecting body dorsally. After hatching, the embryo extends and the position of appendages changes into ventrocaudal position. In the area of the still visible remainder of the blastopore, at the end of the postmandibular rudiment, the anus develops in advanced stages. The mouth is formed by an ectodermal groove just behind the labrum. Contrary to what might be expected theoretically, the ontogenetic development ofPenaeus does not follow the principles of protostomial development, and if this principle is applied rigidly, the natural relationships between invertebrate phyla would be destroyed. The relationships between the blastopore and anus is therefore not a suitable criterion. This phenomenon of holoblastic development can be brought in full accordance with the well-known facts of meroblastic development in arthropods.

Notes: Summary The ultrastructural study of two Chaetognaths' eyeS. tasmanica andE. hamata) pointed out various particularities in the phylum. There is two types of vision: direct and indirect. The sensory cell cilium (for each type of vision) creates a light sensitive system (rhabdomeres or lamellae). Especially in the direct vision it plays a great part in the crystalline lens elaboration. In a phylogenetic way, we have considered the hypothesis of a visual cell turning over. This study confirm the Chaetognaths' group individualisation amidst the animal kingdom.

Notes: Summary Large nerve cell somata are described as bulbar giant cells in the sessile olfactory bulb of teleostean fishes. They are not found in species with a stalked olfactory bulb. They are arranged along the bulbar course of the nervus terminalis. In the “Kaudale Zellgruppe” of Holmgren and the “Kerngebiet des Nervus terminals” of Scharrer a greater part of these giant cells lie at the caudal end of the bulb. It is discussed if these cells are related to the ganglion cells of the nervus terminalis.

Notes: Summary In nearly all terrestrial isopods the cuticle of the tergites is equipped with scale-like, circular or polygonal micro-ridges, whereas in aquatic isopods the cuticle is smooth. Brief descriptions of the microscopic cuticle surface and corresponding SEM photographs are given for 16 isopod species. The function of these structures is considered to be ‘anti-adhesive’, preventing small wet substrate particles from sticking to the cuticle, by minimizing the possible contact area. Particles sticking to the cuticle would hinder the animal's freedom of movement and would prevent a free exchange of water and oxygen between cuticle and environment. The occurrence of the structures as well as the differences in their morphology may be explained by ecological and behavioral differences in the corresponding species.

Notes: Summary Despite the evident efficiency with which ophiuroids discard their arms, there has been no attempt to understand how the arm is equipped anatomically to achieve and recover from autotomy. A light microscope study of the breakage plane ofOphiocomina nigra revealed a series of features which can be interpreted as adaptations for the process of autotomy. The epidermis splits at a constriction which acts as a pre-determined line of least resistance and which serves to leave lateral flaps for the protection of the retained wound surface. The radial nerve breaks at a level where its cross-sectional area is least and which avoids the ectoneural ganglion; at this point the nerve is attached to the floor of the epineural canal by a collagenous structure which may facilitate its rupture. The lateral compression of the radial haemal canal at the breakage plane is believed to assist its closure after autotomy. The sphincters of the radial water vascular canal are described and it is suggested that since they occur just proximal to the breakage plane, one of their functions may be to seal off the canal after autotomy.

Notes: Summary The tibial sense organs in the three pairs of legs from two cricket species have been compared, with special emphasis upon the CoS marking technique (Figs. 1 and 2). The main results are as follows: 1. The tibial surfaces directed outward when the leg is in the normal position have a considerably greater density of innervated hairs and bristles than the surfaces on the inner side of the leg. On the forelegs, hairs and bristles surround the tympana (Fig. 4). This arrangement of the sensilla is thought to be associated with the burrowing habit of the crickets. 2. The special cuticular differentiation (tympana, chitinous ridges) and the particular arrangement of the tracheal system in the vicinity of the auditory receptors (apposition of two tracheal tubes which are in direct communication with one another, Figs. 4, 6, and 7) seem to improve the ability of detection of airborne sound and seem to be important in the frequency analysis carried out by the ears. There are no such differentiated regions in the tibiae of the middle and hind legs. 3. On all three pairs of legs each tibia bears a group of 14–15 campaniform sensilla (Fig. 5); the groups have very similar spatial arrangements. Their nearness to the subgenual organ, and the fact that they are incorporated into the tibial cuticle immediately proximal to the crease, indicate that they measure the loading of the tibia. 4. The subgenual organs in all three pairs of legs consist of ca. 25 sense cells each; these, with their accessory structures, are spread out in a fanlike arrangement, and their dendritic processes bend to run in the hemolymph canal (Figs. 8-13). 5. Only in the anterior tibia is there a complete tympanal organ, with a main process consisting of a row of 30–35 sense cells parallel to the long axis of the leg (Fig. 9). Structures homologous to the caudal and frontal processes of the tympanal organ of the anterior tibia, with 25–30 sense cells, are also to be found in the middle and hind tibia (Figs. 11–13). Therefore it is presumably the main process that is chiefly responsible for detection of airborne sound by the forelegs. The sensory apparatus in the middle and hind legs that corresponds to the caudal and frontal branches of the tympanal organ may well mediate the residual sensitivity to airborne sound which remains after ablation of the tympanal organs (cf. Nocke, 1972; E. Schuhmacher, 1975). 6. The paths followed by the sensory axons from the tibial organs described are almost identical in the three thoracic segments. The subgenual nerve (SGN, Fig. 9) and the tympanal nerve (TN, Fig. 9) each also contain axons of the campaniform sensilla; the tympanal nerve includes, in addition, axons of the sensory cells in the subgenual organ.

Notes: Summary Spermiogenesis in one species from each of the arachnid groups Amblypygi and Uropygi is described by electron microscopy: The whip spider,Tarantula marginemaculata (Amblypygi), and the whip-scorpion,Mastigoproctus giganteus, (Uropygi). In both species the earliest spermatid has a spherical nucleus and soon acquires an anterior acrosome and a posterior flagellar tail. The flagellun is peculiar in having a 9 + 3 axonemal pattern. By the mid-spermatid stage, the nucleus becomes conspicuously elongated, possibly through the agency of a manchette of microtubules. In the late spermatid, the elongated nucleus begins to coil posteriorly; simultaneously the middle piece and the tail flagellum begin to retract into the cell body to form a coiled intracellular axonema. Membranous profiles appear in the peripheral cytoplasm, possibly to accommodate a decrease in the total area of plasma membrane. The mature sperm is a spherical cell, which includes the following organelles in twisted and fully coiled configuration: an elongated nucleus, an acrosome and an acrosomal filament, a long middle piece with helically arranged mitochondria and an intracellular axonema.

Notes: Summary The developmental stages of the colloblasts ofPleurobrachia pileus which are located in the “tentacle root” were studied in detail by electron microscopy, and the origin of the various parts which comprise the mature colloblast was analyzed. In addition to a revised version of the mature colloblast the successive stages of its differentiation are described. The so-called “Klebkörnchen”, which are extra-cellular electron dense granules, do not originate from the colloblasts themselves but from special cap cells (Kappenzellen). Hitherto it was suggested that the intra-cellular p-bodies which are globular particles located at the periphery of the head portion of the cell were the precursor stages of the extracellular Klebkörnchen. The present observations on colloblast development are not in favour of this assumption. The spiral filament which is a highly modified cilium develops from a “basal body equivalent”. A “root organelle” develops from the proximal end of the spiral filament, and at the distal end which lies in the center of the head portion of the colloblast grows the “spheroidal body”. The cone-shaped root organelle with its periodic striation seems to be homologous to a ciliary rootlet. As a special feature, this rootlet bears several hundreds of fine filaments which terminate at the plasma membrane. The spheroidal body and the fibrous tracts are formed out of amorphous material assembled at the distal end of the naked axoneme. The spheroidal body is the most complexe structure ever seen in association with the tip of a ciliary axoneme. In conclusion, the whole apparatus, the spiral filament with the broad membraneous lamellae and its associated structures, i.e. the root organelle and the spheroidal body, is the most highly modified cilium described so far.

Notes: Summary The ultrastructure of the sternal glands of the males ofThrips validus is consistent with the hypothesis that they are involved in pheromone production. The secretory cells, which are strongly modified epidermal cells, are characterized by the abundance of mitochondria and the presence of agranular, tubular endoplasmic reticulum (ATER) and microbodies. Each of the numerous apical microvilli encloses one or several tubular extensions of ATER. Some mitochondria are in close contact with ATER tubules. The mitochondrial matrix is probably involved in the elaboration of the secretory product, which is extruded and possibly modified by the agranular reticulum. The secretion is sudanophilic, but not osmiophilic. No lipid droplets are found in the cytoplasm. After storage in the strongly dilated subcuticular space, the secretion is released by epicuticular ductules with a diameter of about 120 å.

Notes: Summary Cuticular terraces are found in a number of decapod families. In four examples investigations have been made of terrace pattern, terrace morphology, morphogenetic processes, ontogenetic development, and function. InGrapsus grapsus the terrace pattern on carapace and appendages remains constant during ontogeny and the terraces function as frictional resistances in crevices, aiding to escape from avian predators. Histological investigations explain the morphogenetic processes leading to terrace formation.Galathea squamifera has essentially the same terrace pattern and ontogeny asGrapsus, the terraces have the same mechanical function directed against aquatic predators.Gecarcinus lateralis has terraces on the ventral parts of the carapace, their numbers are secondarily increased during ontogeny, and they function as a frictional resistance facilitating the transport of loose substrate in burrowing. InEmerita, the carapace terraces are multiplied during ontogeny and function again as frictional resistance increasing the efficiency of burrowing in sandy substrate. From these results it can be assumed that cuticular terraces in arthropods always function as a frictional resistance in interaction with a solid or loose substrate.

Notes: Summary Two proprioceptors without ciliary structures are described in the head ofOryzaephilus. Both possibly measure the movement and position of the mandible. 1. The ventral muscle receptor of the mandible consists of a muscle fibre and 8 multipolar sensory cells, the perikaryons of which lie near the muscle origin. The muscle fibre runs from the anterior tentorium arm to the ventral basis of the mandible. The sensory cells send a part of their dendrites into the interior of the muscle, where they ramify and end near the Z-bands. Another part of the dendrites forms a compact cord along the ventral side of the muscle. 2. Three other sensory cells form the mandibular tendon receptor. Their perikaryons lie near those of the other eight, and are sheathed together with them. Their dendrites are stretched between anterior tentorium arm and tendon of mandibular adductor muscle, sheathed with glia cell processes. This receptor possibly percepts the adduction of the mandible.

Notes: Summary The structure of the cuticle in the four species of the family Hesionidae(Microphthalmus cf.listensis, M. cf.similis, Hesionides arenaria, juv.Podarke spec.) investigated basically corresponds to that found in all annelids. It consists of an outer, electron dense layer, epicuticle, basal cuticle with a fibrous layer, and numerous microvilli which penetrate the layers and are covered by a more or less dense glycocalyx. However, a rough collagen grid is not developed, the fibers are much thinner and are arranged in a more irregular manner. This corresponds to structures found in archiannelids and polychaete larvae. We consider them here to be reductions of the typical polychaete cuticle and postulate a correlation to the small body size of the species investigated. The quantitative differences in cuticle dimensions in the various body regions and structures can also be explained on a purely functional basis, especially apparent in the comparison of prostomium and body trunk. The pharynx cuticle shows significant structural differences due to the development of an additional peripherical lamellar layer-known to this extent only in gastrotrichs—as well as differently shaped and unusually long microvilli. This character is discussed as a possible synapomorphy for the family Hesionidae.

Notes: Summary 1. The club-shaped antenna ofAglais urticae L. consists of 34–37 segments (scape, pedicel, and flagellar segments; Fig. 1) covered by hairs and scales (Fig. 4a). Only the scape and the pedicel can be moved by muscles (Fig. 6). 2. The head-scape joint may be compared to a ball-and-socket joint. The scape can be moved in various directions by four muscles of the head (Fig. 6a). The scape-pedicel joint functions like a hinge joint, about which axis G3-G4 the pedicel together with the flagellum can be turned upwards by one muscle and downwards by two muscles of the scape (Figs. 6b and 7). This axis, when the antenna is in resting position, makes an angle of ca. 40° (pointing forwards) with the longitudinal body axis when projected into the horizontal plane (Fig. 14). 3. The pedicel-flagellum joint, as all the successive joints, is of almost radial symmetry (Fig. 2). The flagellar segments can only be moved passively by a relatively small amount. 4. Aglais has in its pedicel a highly developed Johnston's organ (Figs. 8–10), the sense cells of which can probably perceive passive movements of the flagellum in relation to the pedicel. The active movements of the antenna can be controlled by Böhm's bristles on the scape and the pedicel (Figs. 3–7). 5. The Johnston's organ, the Böhm's bristles and the antennal muscles are supplied by nerves which arise in the deutocerebrum (Figs. 11 and 12). 6. During flight the antennae are stretched forward almost horizontally (Fig. 1). The adjustment of this antennal flight position is discussed (Figs. 13 and 14).

Notes: Summary Analysis of external forces acting on a climbing mammal under static conditions can be made with the method of free-body diagrams which requires the minimum number of measurements. The analysis must satisfy simultaneously equilibria for both linear translational and rotational effects of the external forces. Solution of the equations generated from the free-body diagram will give the vector direction and magnitude of the contact forces acting on the animal at the supports. Determination of these external forces cannot solve all aspects of climbing adaptations; it provides only the first essential step.

Notes: Summary The duo-gland adhesive systems in three archiannelids(Protodrilus sp.,Saccocirrus sonomacus andS. eroticus) and one turbellarian(Monocelis cincta) were studied by scanning and transmission electron microscopy.Protodrilus attaches to the substrate by the posterior margin of its bilobed and dorso-ventrally flattened pygidium.Saccocirrus also adheres by a bilobed pygidium, but each lobe is ovoid in transverse section, and its median-ventral surface is divided into numerous ridges. Adhesive glands open along the crest of each ridge.Saccocirrus also adheres along bands of adhesive structures that encircle each body segment.Monocelis attaches to the substrate by a crescent shaped area at the posterior margin of the ventral surface. Although the external morphology of the adhesive area is different in each species examined, the basic cellular organization is similar. The adhesive areas contain two types of glands named viscid and releasing. The viscid glands produce granules (0.8–2.0 μm long) that are thought to contain the adhesive that binds the worm to surfaces. The releasing glands secrete granules (0.15–0.2 μm in diameter) that are believed to break the attachment. The releasing granules are identical to those described in other species, whereas the viscid granules have a variety of complex substructures unlike any described previously. The possible homology of the adhesive systems in the archiannelids and those in other taxa with duo-glands is discussed.

Notes: Summary The study of tooth replacement in anguinomorph lizards leads to the following conclusions: 1. The true varanid method of tooth replacement is found only in platynotan lizards and may be correlated with the development of plicidentine. 2. The presence of the iguanid method of tooth replacement could be established for three lineages of extant anguid lizards represented by the generaGerrhonotus (Gerrhonotinae),Ophisaurus (Anguinae) andDiploglossus (Diploglossinae).Anguis fragilis shows a modification of the varanid method. All other anguinoids show a mixture of the varanid and iguanid method of tooth replacement as was noted by Edmund (1960). 3. Parallelism is observed in the pattern of tooth replacement. Teiids parallel the Anguinoidea (Edmund, 1960), andAmphisbaena parallels the Platynota (Gans, 1957). Such cases of parallelism reduce the phylogenetic information content of tooth replacement patterns. 4. Similarities of tooth replacement in platynotans and snakes are considered to be superficial. Apart from the interdental position of the replacement teeth and the lack of formation of resorption pits, many differences can be shown to exist in the pattern of tooth formation, and future work is expected to show differences in the replacement process.

Notes: Summary The antennal-tip sensory complex inAllacma fusca (Collembola) was reconstructed from serial ultrathin sections. The complex contains 16 sensory cells which belong to three spatially separated subunits: (1) a sensory hair; (2) a cuticular protrusion, containing two highly-specialized dendritic outer segments from a single sensory cell encapsulated by an enveloping cell and a gland cell (Figs. 4 and 5); and (3) two sensory cells with partly lamellated, double dendritic outer segments located well away from the cuticular surface (Fig. 3). A phylogenetic evaluation reveals a mosaic of apparently primitive characters, and trends toward higher structural complexity as well as toward reduction (Table 1). There is support for a hypothesis that the receptors of the sensory hair are chemosensitive. The functional interpretation of the other components of the complex is problematic due to their unusual structural properties. The sensory cell beneath the cuticular protrusion is considered to be proprioceptive.

Notes: Abstract Five populations of the bathyal trochid gastropod Bathybembix bairdii (Dall) taken from depths of 579 to 1156 m in the Southern California Continental Borderland were surveyed for levels of genetic variability at 18 presumptive gene loci, using techniques of starch gel electrophoresis. All the populations were highly similar genetically; none of the populations possessed unique alleles. Four of 5 polymorphic loci scored in all the populations displayed statistically significant heterogeneity of allelic frequencies among stations. Only the diallelic fumarase (FUM) locus displayed a trend with depth. The geographic and depth patterns of the genetic variability in these populations do not support the hypothesis that the high levels of genetic variability observed in bathyal populations are an artifact of gene flow between populations differentiated with depth. The 16.2% of the loci heterozygous per individual of B. bairdii is of the same order as the average heterozygosities reported for other deep-sea invertebrate taxa. These reports of high genetic variability in a physically constant and seasonless environment are reviewed and discussed in the context of the trophic-stability hypothesis of Ayala and Valentine and the time, size and divergence hypothesis of Soulé. Evidence is presented that despite the observed correlation of average heterozygosities in benthic marine invertebrates with seasonality of the trophic regime, this is not apparent for an enzyme system (leucine amino peptidase) which might be expected to display this trend if it reflected a genetic strategy to cope with trophic seasonality. The time, size and divergence hypothesis, focusing on population size, accounts for the general features of levels of genetic variability in deep-sea invertebrates.

Notes: Abstract Light-dependent 14CO2 fixation by the algae of Diplosoma virens (Hartmeyer) ranged between about 3 and 27 μmoles mg-1 chlorophyll h-1. The principal first products of 14C fixation were 3-phosphoglyceric acid and phosphorylated sugars, indicating that ribulose bisphosphate carboxylase was the primary carboxylation enzyme. The activity of this enzyme in crude extracts of the algae was 4 to 6 μmoles CO2 mg-1 chlorophyll h-1. The principal end product of 14C fixation by these algae in the ascidian host was a water-soluble oligosaccharide which was an α-1,4-glucan. A maximum of 7% of the 14C fixed was found in insoluble materials of the algae or its host after 60 min 14CO2 fixation. Whether the α-1,4-glucan is a product of algal or animal metabolism remains to be determined.

Notes: Abstract We have measured the photosynthetic assimilation of 14C-carbon dioxide into (1) ethanol-soluble, (2) hot-trichloroacetic acid (TCA)-soluble (polysaccharide), and (3) protein fractions of natural populations of marine phytoplankton. Diurnal studies showed a continuing incorporation of carbon-14 into the protein fraction during hours of darkness. This was accompanied by a concomitant decrease in the proportion assimilated into polysaccharide. When incorporation was measured under constant experimental conditions, the pattern of photosynthesis did not vary from one time of day to another. At one station approximately 12 km south of Boothbay Harbor, the proportion of carbon entering protein showed marked seasonal changes. During the winter, approximately 10 to 20% of the fixed carbon was incorporated into protein. During the summer the value increased to 22 to 35%. Between these times, a transient high value of 37 to 47% of the fixed carbon entering protein coincided with the spring bloom. The increases in proportion incorporated into protein were largely paralleled by equivalent decreases in the polysaccharide fraction. The proportion of carbon incorporated into protein during photosynthesis also increased markedly at reduced light intensities. This increase occurred both when populations were incubated in neutral-density filters and when incubated at increasing depths in the photic zone. There was little consistent and significant difference between the neutral-density filters and depth in the water column, suggesting a minimal role for light quality. The extent of the increased relative rate of protein synthesis at the lower light intensities depended on the nutritional state of the phytoplankton. For example, summer populations from water containing low concentrations of inorganic nutrients responded less dramatically to reduced light intensities than did populations from nutrient-rich waters.

Notes: Abstract Observations were made and quantitative samples of non-canopy kelps were collected, using SCUBA, at 9 subtidal sites off southern Kodiak Island in May, 1976. At a 10th site, only observations were made. The most abundant species in the quadrats were Laminaria dentigera, L. yezoensis, Pleurophycus gardneri, Agarum cribrosum, and Alaria marginata. We found fertile plants of all these species. L. dentigera dominated at all sampled sites except one within a bed of Nereocystis luetkeana, where P. gardneri was dominant. L. yezoensis was dominant at the site which was visited but not sampled. The average wet weight of non-canopy kelps in the 55 samples was 12 kg m-2, and the quadrat range was 2 to 35 kg m-2. The reported ranges of P. gardneri and Alaria marginata are extended westward from Montague Island (147°22′W) to Bumble Bay, Kodiak Island (154°43′W), where A. marginata was found at a depth of 8.5 m.

Notes: Abstract Variation amongst wild populations of Scytosiphon lomentaria (Lyngbye) Link is shown to be of a continuous nature, and the species cannot be readily segregated into distinct subspecific taxa on the basis of morphological characteristics. Zoospores derived from plurilocular sporangia developed asexually into cylindrical thalli under long and short days at 16°C. The progeny of some cylindrical thalli included microthalli bearing plurilocular sporangia or unilocular sporangia. Cylindrical forms of S. lomentaria were obtained in culture from wild microthalli of two kinds, bearing either plurilocular or unilocular sporangia. The microthalli differ morphologically from the ralfsioid stages commonly known to be plethysmothalli and sporophytes of S. lomentaria, but closely resemble the microthalli derived from cultures of wild S. lomentaria.

Notes: Abstract Annual landings of shrimp (Crangon crangon) in the Lancashire and Western Sea Fisheries District (UK) have previously been predicted 1 year in advance on the basis of rainfall and air temperature records of the previous year. For the port of Lytham, abundance of shrimp has been found to be correlated with mean sunspot number. Since sunspot number can be predicted fairly accurately, this correlation has given the prediction of landings a greater accuracy than was formerly possible. Sunspot numbers can be predicted for a considerable period of time in advance, and therefore abundance of C. crangon at Lytham can be estimated for several years.

Notes: Abstract In juvenile and adult Sepia officinalis (L.) of the Bassin d'Arcachon, France, the copper and iron contents of blood, hepatopancreas, branchial gland, branchial heart, branchial heart appendages, heart ventricle, and pancreatic appendages were determined by flameless atomic absorption. Despite the significant differences between the absolute values of the copper and iron concentrations in the different organs, a certain parallelism can be demonstrated in the ability to concentrate the two metals. The hepatopancreas, as the most important storage organ, shows the highest concentrations of copper and iron, followed by the branchial heart system with distinctly lower values. The cytolysosome-like dense bodies in these tissues of s. officinalis and of Octopus vulgaris (Lam.) can be characterized as the cellular sites of storage by histochemistry and electron microscopy. The low copper content of the branchial gland does not disprove the conception of a hemocyanin synthesis in this organ; biochemical experiments indicate a subsequent incorporation of copper released by the endoplasmic reticulum (ER) of the gland.

Notes: Abstract Gonyaulax polyedra Stein exhibited a combination of photoadaptive strategies of photosynthesis when only a single environmental variable, the light intensity during growth, was altered. Which of several biochemical/physiological adjustments to the light environment were employed depended on the level of growth irradiance. The photoadaptive strategies employed over any small range of light levels appeared to be those best suited for optimizing photosynthetic performance and not photosynthetic capacity. (Photosynthetic performance, P i, is defined as the rate of photosynthesis occurring at the level of growth irradiance.) Among all photosynthetic parameters examined, only photosynthetic performance showed a consistent correspondence to growth rates of G. polyedra. Above 3500 to 4000 μW cm-2, where photosynthetic performance was equal to photosynthetic capacity, cells were not considered light-limited in either photosynthesis or growth. At these higher light levels, photosynthetic perfomance, cell volume, growth rates and respiration rates remained maximal; photosynthetic pigment content varied only slightly, while the photosynthetic capacity of the cells declined. At intermediate light levels (3000 to 1500 μW cm-2), photosynthesis, not growth, was light-limited, and photoadaptive strategies were induced which enhance absorption capabilities and energy transfer efficiencies of chlorophyll a to the reaction centers of G. polyedra. Photosynthetic capacity remained constant at about 280 μmol O2 cm-3 h-1, while photosynthetic performance ranged from 100 to 130 μmol O2 cm-3 h-1. Major increases in photosynthetic pigments, especially peridinin-chlorophyll a-proteins and an unidentified chlorophyll c component, accompanied photoadaptation to low irradiances. Maximal growth rates of 0.3 divisions day-1 were maintained, as were respiration rates of about-80 μmol O2 cm-3 h-1 and cell volumes of about 5.4×10-8 cm-3 cell-1. Below about 1250 μW cm-2, photosynthesis in G. polyedra was so light-limited that photosynthetic performance was unable to support maximal growth rates. Under these conditions, G. polyedra displayed photostress responses rather than photoadaptive strategies. Photostress was manifested as reduced cell volumes, slower growth, and drastic reductions in pigmentation, photosynthetic capacity, and rates of dark respiration.

Notes: Abstract Two experiments were performed during 1975 and 1976, in which cadmium was added to seawater and its plankton enclosed in plastic containers moored in Saanich Inlet (Vancouver Island, Canada), as part of the CEPEX project. In both experiments, two enclosures (ca. 68 m3 each) were used; one was spiked with about 1.3 μg l-1 cadmium, while the other served as a control, to assess the fate of the added metal and its effect on marine phytoplankton. In both experiments, the pattern of biological events was found to be very similar for the cadmium-treated bag and for the control. Furthermore, there were no marked differences in the phytoplankton species composition, thus indicating that at this concentration level cadmium did not affect the ecosystem. The rate of removal of cadmium by biological processes was relatively slow. The fraction of metal accumulated (for 2 and 4 weeks, respectively) in the settling material was less than 1% for the cadmium-treated bags. Experiments on the mechanism of cadmium binding indicated that the major part of the particulate metla is loosely bound to the outer cell membranes.

Notes: Abstract Experiments on enzymatic (in vitro) and in vivo CO2-fixation using a variety of marine Rhodophyceae such as Porphyra umbilicalis (L.) J.Ag., Rhodomela confervoides (Huds.) Silva, Corallina officinalis L. and Chondrus crispus Stackh. revealed that carbon assimilation in the Rhodophyceae is almost exclusively performed by photosynthesis via ribulose-1, 5-di-phosphate carboxylase, whereas light-independent CO2-fixation via β-carboxylation by phosphoenolpyruvate carboxykinase scarcely exceeds 1% of the total carbon fixation potential of the plants. Activity of phosphoenolpyruvate carboxylase could not be detected. With respect to the main accumulation products of photosynthetic CO2-fixation, the Rhodophyceae investigated are not uniform: Corallina officinalis L., Rhodymenia palmata (L.) Grev., and Gigartina stellata (Stackh.) Batt. have been found to accumulate 14C in the neutral compound floridoside (=2-O-glycerol-α-D-galactopyranose), whereas Delesseria sanguinea (Huds.) Lamour., Ceramium cubrum (Huds,) C.Ag., and Rhodomela confervoides (Huds.) Silva, representing members of the Delesseriaceae, Ceramiaceae and Rhodomelaceae, respectively, do not photosynthesize floridoside, but show intense 14C-labelling in an acidic constituent, mannosidoglycerate (= digeneaside). This compound is reported for the first time as a rapidly 14C-labelled and accumulated photosynthate in a variety of red algal species exclusively belonging to the Ceramiales.

Notes: Abstract Observations on the subtidal seastar Pisaster brevispinus (Stimpson) indicate that this predator can extend the central tube feet into sand-mud substrate for a distance roughly equal to the radius of the seastar. Field and laboratory evidence demonstrates the use of the elongated tube feet by the asteroid for the capture of burrowed prey items. A relationship between predator size and the size of juveniles of the deep-burrowing clam Tresus nuttallii taken as prey is a product of the ability of larger seastars to extend the tube feet further into the substrate and capture deeper prey. The role of P. brevispinus as an important subtidal predator along the Pacific Coast of North America is discussed.

Notes: Abstract The glycogen content of whole body or muscle of 14 species of polychaetes was determined, and the activity, co-factor requirements, and substrate affinity of glycogen synthetase from muscles of 4 of the species were measured. Species average glycogen concentrations were positively correlated with the risk of anoxia each species faced in the field. Total activity of glycogen synthetase was not correlated with glycogen concentration in muscle, but polychaetes most likely to experience anoxia had the highest proportion of the enzyme in the active (co-factor independent = I) form; moreover, in such species, the glycogen synthetase had the highest affinity for substrate. It was concluded that evolutionary adaptation to oxygen-poor habitats occurs through qualitative changes in enzyme properties rather than through quantitative changes in enzyme production.