ALBERT

Notes: Summary The eyes of Rostanga pulchra larvae develop immediately behind the velar lobes approximately 20 days after hatching. Each is a pigmented cup with a lens occupying the concavity of the cup. The eye is composed of a single corneal cell, 7 sensory cells and 8 pigment cells. Sensory cells are of the rhabdomeric type and bear microvilli as their receptive surface. The eye connects to the inner dorsal region of the optic ganglion through a nerve that consists of axons arising from the 7 sensory cells. The optic ganglion, in turn, joins the lateral region of the cerebral ganglion. The possible functions of the eye are discussed in relation to larval behavior.

Notes: Summary The small cells of the midgut glands of Armadillidium vulgare, Oniscus asellus, Porcellio scaber, and Alloniscus oahuensis were examined by transmission electron microscopy, X-ray microanalysis, histochemistry, and atomic absorption spectroscopy. Inclusions containing large amounts of heavy metals were the most prominent feature of these cells. Various areas of the midgut glands exhibited large differences in storage capacity. Juveniles were free of lead.

Notes: Summary The oesophageal epithelium of eleven sea-water and four fresh-water teleosts was studied by light and electron microscopy. In sea-water species, the three main regions from pharynx to stomach are: a thick stratified pharyngeal epithelium with complex foldings and numerous mucous cells, and a simple microvillous columnar epithelium in the middle and posterior part. In fresh-water species, foldings are simple, the first two regions occupy the whole length, and no microvillous epithelium is observed. The adaptation from fresh-water to sea-water is characterized by the development of the third, microvillous epithelium. Different microridge cells appear in the mucous region of fresh-water and sea-water Anguilla anguilla oesophagus. The ultrastructure of the microvillous epithelium suggests an active transport of ions along the lateral membranes with water recycling in frequently dilated intercellular spaces.

Notes: Summary The cricket Cycloptiloides canariensis (Gryllidae, Mogoplistinae) has compound eyes of the eucone apposition type. They consist of relatively few (about 160–190) ommatidia with a wide angle of divergence. Each ommatidium has two primary pigment cells, four Semper cells and eight retinula cells whose four distal rhabdomeres are arranged around the tip of the crystalline cone. The screening pigments are contained mainly in the primary pigment and retinula cells, while the secondary pigment cells are sparsely pigmented. The dorsal eye region can be distinguished by the following characteristics: lack of dioptric apparatus (flat, unfacetted cornea, absence of cones), densely packed rhabdomes in approximately parallel orientation extending distally to the cornea and possessing a markedly increased cross-sectional area in comparison with those of normal ommatidia. Screening pigments are absent. The importance of this dorsal region will be discussed.

Notes: Summary The pore plates of Pimpla are about 40–75 μm long and 5–7 μm wide. Through a central cuticular canal they are in contact with the lumen of the antennae. Under the perforated plate blind-ending tunnels extend in the distal and proximal directions. It is extremely probable, that the pore plates of Hymenoptera are derivatives of basiconical sensilla. The ontogeny of the pore plates was followed back to the beginning of the deposition of the cuticulin layer. Each pore plate ‘anlage’ contains 40–47 sensory cells and 6 enveloping cells. Envelope cell 1 secretes the dendritic sheath, which is fully reduced during ontogeny. The envelope cells 2a and b (trichogen cells) are mirror images of each other, they form the perforated plate and the pore tubules. On both sides of the trichogen cells lie the envelope cells 3a and b (tormogen cells), they also form mirror images of each other. The tormogen cells secrete a cuticular ledge, that surrounds the perforated plate. In the outer distal position lies envelope cell 4, which encircles the pore plate ‘anlage’ in the proximal direction. Envelope cell 4 folds in and retreats from the epithelium surface, thus forming a ‘joint-furrow’ around the pore plate ‘anlage’. The doubling of the trichogen cell is unusual in insects and so far has been observed in basiconic sensilla and pore plates of Hymenoptera only. The doubling of the tormogen cell until now could be established only in basiconic sensilla of Cephus and of Xiphydria (Hymenoptera, Symphyta). In pupae 3–4 days old the trichogen and tormogen cells begin to retreat from the perforated plate. In the imago this outer receptor lymph cavity is nearly completely filled by the branched outer dendritic segments.

Notes: Summary During each moult the anal glands in Rhapidostreptus virgator are partly dissolved and subsequently rebuilt and enlarged by embryonic cells within the anal sac epithelium. An embryonic cell undergoes two mitoses thus producing the four cells which are present in a glandular unit. During the genesis of the glandular units each of the latter secretory cells produce a ciliary process, which is believed to serve as a mould for the canal cell, which in turn secretes the cuticular efferent duct.

Notes: Summary The fertilized egg of the freshwater bryozoan Plumatella fungosa develops into an elongated ovoid larva, which after embryogenesis in the embryo sack is released into the surrounding water. During the short free-swimming stage the larva is characterized by the presence of several locomotive and attachment cell types. The ectodermal epithelial cells are provided with numerous cilia. The cytoplasm of the epithelial cells contains numerous mitochondria, Golgi bodies, and ribosomes. Gland cells containing vacuoles of flocculent, lightly staining secretion material were observed between the epithelial cells in the anterior pole of the larva. From a neural center beneath the epidermal cells in the anterior pole nerves emerge in a radial direction. These nerves may include up to 30 axons. Beneath the nerves are a lamella of collagenous fibers and a layer of muscle cells. Internally the larva possesses a coelomic cavity bounded by a squamous epithelium. At the anterior pole large, irregular cells rich in rough endoplasmic reticulum and lipid droplets are seen associated with the coelomic wall. It is concluded that the P. fungosa larva is a true planctonic larva, although highly modified and reduced. There is an acceleration of adult features with differentiation of functional zooids within the larval body. This acceleration may be an adaptation to life in freshwater.

Notes: Summary Origin and formation of the body wall epidermis of the ancestrula in three species of gymnolaemate bryozoans were analyzed by scanning and transmission electron microscopy. In the ctenostome Bowerbankia gracilis, the aboral pallial epithelium forms the entire cystid epidermis, whereas in the anascan cheilostome Bugula neritina, the wall and roof regions of the internal sac form the epidermis. In the ascophoran cheilostome Watersipora culcullata, however, both the pallial epithelium and internal sac contribute to the body wall epidermis. In spite of these different origins, the tissues involved in production of the exoskeleton share a common ultrastructure. The various patterns of metamorphosis described here indicate that ancestrular body wall origin may be an important character in the analysis of phylogenetic relationships within the Bryozoa.

Notes: Summary The three anterior adhesive papillae of Diplosoma macdonaldi serve to attach the larva to the substratum at settlement. Each is a cup-shaped, epidermal organ with a bulbous axial protrusion. Approximately 50 sensory neurons (anchor cells) are distributed around the rim of each papillar cup within the epithelium. An axon from each passes within the wall of the cup to the base of the papilla and thence in the hemocoel to the visceral ganglion. Microvilli arising from anchor cells form a network below the outer cuticle of the tunic. Ten to 15 sensory neurons of a second type (basal cells) are situated within the epithelium around the base of each papilla. A single cilium arises from an invagination in the soma of each basal cell and extends either proximally or distally along the surface of the epithelium. An axon from each basal cell joins the anchor cell axons to project to the visceral ganglion. We infer that papillar sensory cells allow a larva to sample the characteristics of the substrate at potential sites for settlement and metamorphosis.

Notes: Summary Each sessile eye comprises about 60 ommatidia with large lenses (diameter 100–150 μm), spherical crystalline cones, and hypertrophied rhabdoms (diameter about 100 μm). The cones are formed by two main cone cells, and in addition two accessory cone cells are present. Seven retinula cells contribute to the rhabdom, which is fused distally and open proximally (separated rhabdomeres). A special cell type, previously designated ‘hyaline cells’ are shown to be reflecting pigment cells. These cells form a well-developed tapetal layer. Distal pigment cells screen neighbouring ommatidia. Further, the eye is delimited by two membranes homologous to the fenestrated and eye capsule membranes present in several other isopod groups. The hypertrophied rhabdoms and the elaborate tapetal layer separate the morphology of the Cirolana eye from that of other isopod eyes. These structural features makes the Cirolana eye a case of convergent development with several other deep water living crustaceans.

Notes: Summary The lateral retinae of some advanced salticid spiders are found to conform to the ultrastructural descriptions of Eakin and Brandenburger (1971). Retinae of two forms supposed by taxonomists to be primitive, Portia and Lyssomanes, are described for the first time. Portia exhibits the overall relationships between pigmented and non-pigmented glial processes and receptors typical of advanced forms, but (i) non-pigmented processes are elaborately and irregularly divided and do not contain microtubules; (ii) four pigmented processes enclose the complex of receptor+non pigmented glial processes instead of six. The rhabdomeral layer of the retina of Lyssomanes is not invaded by processes of the pigmented glia, which forms a pigmented screen proximal to the receptive segments. The receptors are separated from each other by thin lamellae of non-pigmented glia whose somata lie in the normal position amongst those of the receptors. The retinal organisation resembles that of some nocturnal spiders such as Menneus (Blest et al. 1980). The posterior median retinae of Portia are identical in construction to those of the other accessory eyes, although smaller. Those of Lyssomanes and advanced salticids are vestigial. Shedding of photoreceptor membrane during turnover appears to be largely intracellular in all these forms, in contrast to Plexippus in which an extracellular route has been described.

Notes: Summary The terminal organ, a structure enabling pelagosphera larvae of Sipuncula to form temporary attachments to substrata, was examined behaviorally and with light and electron microscopy for larvae of Golfingia misakiana, collected from the Florida Current. The terminal organ appears as a retractile rounded knob with a short neck joining the posterior extremity of the trunk. It can attach larvae directly to substratum or can secrete a tether-like mucus strand about which the organism moves. In unattached larvae, the terminal organ is often placed in the mouth. The terminal organ of a 5.5 day old larva consists of 29 cells: 8 epidermal, 3 mucus, 2 tension-bearing, 5 sensory, 10 retractor muscles and 1 unknown cell. The mucus cells are presumed to release the adhesive material while the microvilli on the tension-bearing cells, with their dense cores of microfilaments, bear the strain. The latter are joined directly to the retractor muscles which originate on the dorsal body wall near the anus. Two of the sensory cells terminate within the cuticle flanking the adhesive pore and are assumed to be cuticle strain receptors. Three sensory cells terminate in cilia that extend posteriorly from the pore. These may function in substratum evaluation prior to temporary attachment, or settlement preceding metamorphosis. The terminal organ is compared to adhesive organs in other soft-bodied metazoans and although it approximates the structure found in some rotifers, it is considered to be independently evolved within the Sipuncula. The terminal organ can be understood as an adaptation in young larvae for protective attachment and facilitation of feeding whereas, in older larvae, it may only function in substrate evaluation prior to settlement.

Notes: Summary Crinoid tube feet occur in groups of three (podial triplets) that behave as functionally integrated units for food particle collection. Scanning electron microscopy shows that each triplet member has a distinctive morphology related to its behavioural role in feeding. Particularly conspicuous features are papillar distribution, papillar processes, ciliary tracts, and pores that are the openings of mucous glands. The primary podia serve for initial particle capture. The secondaries, together with lappets, play a major role in particle transfer from the primaries and may themselves also entrap particles. The tertiaries manipulate particles within the food groove after their transfer from the other podia. The tertiary podia use their papilla-free medial faces to compact mucusbound particles into boluses. In pinnules, boluses are transferred to the food groove midline by tertiaries, then propelled orally by paddling actions of these podia. Boluses are also transported by the medial ciliary tracts of the pinnules and arms. Bolus transport by tertiary paddling is probably more effective in the pinnular than the arm food groove. Short lateral ciliary tracts at the base of each primary podium may guide boluses into the main ciliary stream or may be cleansing currents. As the ultimate site of food particle collection, compaction and transfer, podial triplets represent a third adaptive level of an intricate suspension feeding system in which the first (arm postures) and second (pinnule orientations) adaptive levels are related to increasing collecting efficiency in diverse ambient flow.

Notes: Summary The accessory eye of an African giant snail, Achatina fulica, is situated under an extension of the cornea of the main eye and invariably possesses a small lens. The accessory retina is composed of type I and type II sensory cells and nonpigmented supportive cells that closely resemble corneal cells. Type I cells contain photic vesicles, and their microvilli are comparable in length and density to those of the main retina. Type II cells bear stubby microvilli and various vesicles, but no photic vesicles. The ratio of type I to type II cells is about two to one in both accessory and main retinas. Certain electron-opaque cells scattered among corneal cells possess numerous photic vesicles and twisted microvilli that are confined to intercellular spaces. The cavity of the accessory eye, being separated from that of the main eye by two boundary layers, is filled with debris, such as granules, vesicles, and whorls.

Notes: Summary The long and slender spines of Diadema are highly flexible, although their skeleton consists mainly of CaCO3 and behaves optically like a single monocrystal of calcite. The flexibility is due to the shape of the spine skeleton as well as to the material properties of the echinoderm calcite. The spine skeletons are hollow beams consisting of radial wedges or septs. The shape of the septs shows a broad base situated at the periphery of the cross section, producing a high load-bearing capacity with minimum weight. Furthermore, material is concentrated at the base of the spine in such a way that the strain of the structure is kept constant along the axis. The septs are connected with one another by a few transverse bars positioned as closely as possible to the axis. The load-bearing parts of the septs are free. They have small diameters similar to flexible glass fibres. The stiff spines of other echinoids are also mainly built by radial wedges, but the spaces in between are closely filled with transverse bars. On the surface of stiff spines there are low grooves between the septs. The echinoid spines are covered with an epithelium which shows a basiepithelial nerve plexus. In the stiff spines this plexus forms cords which lie protected within the superficial grooves mentioned. In the flexible spines of Diadema the cords are deeply sunken in the spaces between the septs. In this manner the nerve cords are largely free from the tensile stresses to which the spine's surface is exposed. The flexible spines were used to determine the material properties of echinoderm calcite. Young's modulus was determined for fresh (live) spines, dry spines, and cleaned spine skeletons. Fresh spines show the highest elasticity, and their Young's modulus is significantly below the Young's modulus of the other test groups. The echinoderm calcite does not show the cleavage planes of mineral calcite, and probably this feature contributes to the high flexibility of echinoderm calcite.

Notes: Summary Heat stressed pigeons dissipate heat by panting and gular flutter which is associated with upper esophageal pulsation; these activities depend on evaporative cooling and convection from mucosal surfaces. The collar plexus, an unusual subcutaneous system of erectile veins, is the specialized vascular apparatus that seems to serve as the heat exchanger for gular flutter and upper esophageal pulsation. The collar plexus lies between the dermis and a deeper muscle sheet, extending from the head to the thoracic inlet in mature pigeons. The slightly filled plexus is inconspicuous, resembling an ordinary venous bed, and consists of thick-walled veins having small lumina, similar to arteries. When moderately-filled, the veins of the plexus distend and abruptly transform into “beaded” veins with contorted, sacculated expansions separated by constricted segments. During heat stress, engorgement of the plexus occurs rapidly by continual flow over arteriovenous anastomoses that empty arterial blood directly into the beaded veins. Constriction of veins draining the plexus impedes venous return to the jugular veins, thereby maintaining tumescence of the plexus. Disgorgement of the plexus also occurs abruptly. Intimate contact between the deep aspect of the engorged plexus and the trachea and upper esophagus provides for heat transfer from the plexus to the mucosal surfaces of these structures where evaporative cooling takes place. During esophageal pulsation the esophageal surface extends and augments the respiratory dead-space area used for evaporative cooling. Thus a possible advantage of cooling by upper esophageal pulsation is that, like gular flutter of the oropharynx, it may minimize the amount of air that must pass over gas exchange surfaces, thereby limiting the washout of CO2 and consequent acid-base disturbances that occur during panting in extreme heat stress. Ability to inflate the esophagus is of general occurrence among the pigeons and doves (Family Columbidae). The collar plexus is also widespread, having been found in representatives of five of the examined six main subdivisions of the Columbidae.

Notes: Summary 1. The development of taste hairs and tactile hairs of the fly Protophormia terraenovae is described using light microscope, scanning, and transmission electron microscope methods. 2. The development of taste hairs proceeds in the same way on tarsi, labella, and wings. First the dendritic outer segments of ciliary origin become visible above the hypodermal cell surface [2 days after pupariation (AP) at 19° C]; then the dendritic sheath starts growing out and finally the trichogen process follows. In a typical intermediate stage (‘stage C’) the distal sections of the dendrites float freely in the fluid surrounding the pharate adult. The more proximal sections are enclosed by the dendritic sheath around which the trichogen process is wrapped (4 days AP). The protruding dendrites disappear when the cuticle starts being deposited on the fully grown trichogen process, and the sheath vanishes later (9–10 days AP or 1 day before eclosion). The development is discussed with respect to the known structural organization of the adult hair. 3. In the tactile hairs the single dendrite which grows outwards is completely covered by the dendritic sheath and lies beside the trichogen process [stage C(m)]. 4. The taste and tactile hair development proceeds in the same way on legs isolated from the pupa after disc eversion in an artificial medium containing ecdysterone. 5. To check that both these patterns of development are widespread the development of taste and tactile hairs of the first instar cercus of the cricket Acheta domestica was studied with the light microscope: Both hair types pass through identical early stages.

Notes: Summary The larval endostyle consists of two ridges of secretory cells, which correspond to the two paired muciparous bands in the endostyles of the adult Branchiostoma, most tunicates, and the lamprey ammocoete. The peculiar shape of the larval endostyle is an effective adaption for food-trapping in the asymmetrical body of the larva. Contrary to general belief, the internal opening of the club-shaped gland is the site of the secretory release, while the exernal opening is an inlet for sea water. The water is mixed with the mucous substance, probably containing neutral glycoproteins, which is produced in the gland tube. This material is released through the internal pore dorsally in the buccal cavity at a position where it is carried with the endostylar secretion towards the intestine. The club-shaped gland is not part of the food-trapping mechanism, but it is apparently an important larval gland which produces substances which may act in the processing of the food or in some other way may direct larval life.

Notes: Summary Baker's yeast (Saccharomyces cerevisiae) suspended in the water that enters the incurrent canal system of the fresh-water sponge Ephydatia fluviatilis by way of the dermal pores is carried into the mesenchyme, where it is deposited against the surface of the flagellated chambers that generate the current. In the first phase of ingestion, as soon as the imported yeast cells have touched the choanocytes, the latter send extensive pseudopodia out into the mesenchymatic space to phagocytise the yeast cells there. Similar responses are elicited in the mesenchymatic cells during the second phase of ingestion and later in the pinacocytes of the excurrent canal system. All the cells of Ephydatia fluviatilis can phagocytise yeast cells. However, the yeast cells cannot be digested by the sponge cells and in the course of a few hours to 2 days they are expelled from the cells into the mesenchyme, whence they move transcytotically through the endopinacocyte lining into the excurrent canal system and eventually pass through the oscular tube to the exterior.

Notes: Summary The tissues of a fully grown echinoid skeleton are described using the primary spines of E. tribuloides as an example. Cidaroid spines are covered with an external, polycrystalline cortex, but as long as they are still growing they are covered with an epithelium. The mineral skeleton is embedded in the mesodermal stroma tissue which largely consists of fluid. Different types of mesodermal cells float within this fluid, but the sole characteristic stroma cells are the sclerocytes which are anchored to the calcite trabeculae by means of a cytoplasmic stalk. The latter spreads over the surface of the young trabeculae as a thin, continuous sheath, but on fully grown trabeculae it ramifies into numerous filiform processes (dp). The sclerocyte cell body is surrounded by a boundary layer which, however, is absent in the distal sheaths or filiform processes. The cytoplasm of the sclerocytes is electron-translucent and contains numerous free ribosomes. Sclerocytes which lie below the epithelium produce the cortex layer, and in the end the extracortical stroma as well as the epithelium vanish, and the cortex becomes external. Phagocytes within the stroma are at least as numerous as sclerocytes. They have a dense cytoplasm with long, straight pseudopodia protruding from it and running through the midst of the pore space. In normal conditions the pseudopodia do not touch the trabeculae. In a single instance, however, a phagocyte was demonstrated to etch a trabecula. Its etching face was crowded with clear vesicles which are not found elsewhere.

Notes: Summary Reabsorption of calcite is known to occur in echinoid endoskeletons. The structure of the operating cells is described using ‘Prouho's membrane’ as an example, which dissolves the skeleton of cidaroid spines within a thin section. After that the distal part of the spine is shed, and a new shaft grows out of the remaining stump. The calcoclast function is exercised by phagocytes which are also numerous in normal spine tissues. If the spine is highly damaged, however, the phagocytes assemble at a defined level and melt into a single syncytium, called Prouho's membrane. They fulfill three functions: (1) they show an extreme phagocytotic activity and ingest cells of the distal spine part, (2) they block off the surviving stump from the distal part shed later, (3) they etch through the calcite trabeculae in order to detach the distal spine part. The dissolution of the calcite starts with circular bulges, but in the end extremely thin etching lamellae run transversally through the trabeculae.

Notes: Summary The ommatidia of the compund eye of the krill, Meganyctiphanes norvegica, are composed of the following cell types: corneagenous cells, main cone cells, accessory cone cells, distal pigment cells, and retinula cells. The corneagenous cells secrete the cuticular lenses, below which the crystalline cones are present. The bipartite crystalline cone is formed within the main cone cells, whereas the accessory cone cells invest the distal part of the cone and proceed proximally in the retina to the basement membrane. Six distal pigment cells are arranged around each ommatidium, though shared by adjacent ommatidia. The seven retinula cells form the rhabdom, and penetrate the basement membrane as axons. The basement membrane is formed by the conjoined extended prolongations from the accessory cone cells and sheets from the basal pigment cells.

Notes: Summary Apodotrocha progenerans n.gen., n.sp. from tidal beaches or shallow waters on the east coast of the USA (Massachusetts) is a gonochoristic interstitial polychaete (length ca. 600 μm; six trunk segments), that lacks parapods, setae, and fleshy appendages, but has three characteristic caudal cirri. The habitus greatly resembles a larval stage of the Dorvilleidae, a family with which it also shares several anatomical features as revealed by ultrastructural investigations. Great similarities to the so-called archiannelids belonging to the Dinophilidae are also apparent, thus demonstrating the close phylogenetic relationship of the latter family to the Dorvilleidae.

Notes: Summary The ovary of the red abalone consists of a series of trabeculae or polygonal chambers that extend from the ovarian wall toward the wall of the digestive gland. The ovarian wall consists of smooth muscle cells and bundles of collagen fibrils, that extend into the trabeculae. Presynthetic, synthetic and early postsynthetic oocytes are surrounded by a single layer of follicle cells which bind these oocytes to the trabeculae. The follicle cells contain bundles of microfilaments. Mature oocytes lack a follicle cell layer and are found free in the chambers formed by the trabeculae. Each oocyte is surrounded by a vitelline layer, a chorion, and a thick jelly coat. Stages in the formation of these layers are described. It is suggested that prior to spawning the trabeculae detach from the wall of the digestive gland and retract toward the ovarian wall. Contractions of the ovarian wall may force oocytes out of the ovary into the seawater where fertilization occurs.

Notes: Summary The development of the aesthetascs of Neomysis integer (Malacostraca, Mysidacea) and Idotea baltica (Malacostraca, Isopoda) were investigated by electron microscope methods. Basically the aesthetascs of both species develop according to the same pattern. The newly formed sensillar shafts lie invaginated within the epidermal tissue. They are formed by numerous enveloping cells, which are arranged telescopically one by one. Each enveloping cell secretes a definite portion of the new shaft cuticle. The innermost enveloping cell extends furthest distally and deposits the cuticle of the future shaft tip. The outer enveloping cells produce the cuticle of the more proximal shaft portions. Whereas the morphogenesis of the aesthetascs of both species is uniform, the moulting processes are different. In the aesthetascs of Neomysis the morphological basis for a continuation of the sensitivity remains until ecdysis, as an intact dendritic connection between the sensory cells and the old shaft is maintained. In Idotea, the aesthetascs cease to function during the early moulting stages.

Notes: Summary A structural and ultrastructural investigation of epidermis in the esophageal region of Carinoma tremaphoros is correlated with analysis of burrowing locomotion. The pseudostratified epidermis contains multiciliated epidermal cells, gland cells and granule-containing basal or interstitial cells resting on a well-developed basement membrane. Both circular and longitudinal muscles are present within the epidermis, woven between the cells of this layer. These muscles are well-developed along the anterior region of the worm and, like the subepidermal muscles, are a variation of obliquely striated muscle without continuous Z-rods. Epidermal muscles originate as branches from the underlying mesodermal musculature and cross the basement membrane into the epidermis, confirming earlier observations. These muscles are unrelated to myoepithelial epidermal cells described in other metazoans. This condition is considered a secondary derivation consistent with the Gastraea-Enterocoel theory of bilateral metazoan evolution. Carinoma is a peristaltic burrower. Peristaltic waves are limited to the anterior region of the worm where the diameter of the rhynchocoel is maximal and the bilayered epidermal musculature is strongly developed. Following a consideration of burrowing mechanics in annelids, supernumerary epidermal muscles in Carinoma are interpreted as prerequisites to peristaltic burrowing effectiveness in a non-segmented coelomate.

Notes: Summary Light- and dark-adapted ocelli (LL and DD for 30 h) of seastars were studied by thin sectioning and freeze-fracture techniques for electron microscopy, and by histofluorescence. Lighting conditions affected the ultrastructure of the sensory microvilli, which became longer, more numerous, and more regularly arranged in darkness. A significant reduction in the density of intramembranous particles (IMPs) occurred in the sensory microvilli of LL specimens (6,600/µm2 in DD, 3,000/µm2 in LL) and, to a lesser extent, in the apical projections, but not in other membranous components including the cilia of the sensory cells. Additional observations on four other species revealed higher densities of IMPs in sensory microvilli than those in cilia. The fact that IMP densities of the LL sensory microvilli and the pinocytotic vesicles were nearly the same was considered to show the relationship of the two membranous structures. A specific fluorescence, indicative of the presence of retinal-based proteins, appeared only in the ocellar lumen of DD specimens, but practically none in LL ones. It was suggested that in the seastar ocelli the sensory microvilli are the primary photoreceptive sites and that they contain a rhodopsin-like substance. These conclusions support the view that asteroid photoreceptors are microvillar and not ciliary.

Notes: Summary Rhabdom formation was examined at the EM level in two members of the Chrysomelidae with different patterns of open rhabdoms (Leptinotarsa decemlineata — ponticulus pattern; Crioceris asparagi — insula pattern). Rhabdom morphogenesis, especially that of the central rhabdomere system of R7 and R8 is slightly different in both species and does not reveal which of the two patterns is primitive and which is derived. A close spatio-temporal correlation was found in L. decemlineata between the occurrence of a transitory modified cilium and the beginning of rhabdomere formation. The significance of this finding and its possible functional implications for the development of insect photoreceptor cells are discussed.

Notes: Summary The morphology of sternal glands and associated cuticular specializations are described for female polistine social wasps. Their distribution among 25 of the 28 genera of the subfamily is examined in light of what is known of the functions of these glands. Species in which queens found colonies independently of workers (four genera plus part of Ropalidia) have clusters of ducted gland cells on the sixth (terminal) gastral sternite. In all species examined the gland cells open into a tuft of long setae which probably functions as a reservoir/applicator brush. There is at least circumstantial evidence for all five genera that this gland produces an ant repellent substance that is smeared onto the nest petiole, where it serves as a defensive barrier against ants. The remaining genera (20 plus part of Ropalidia) consist of species in which queens are accompanied by a swarm of workers in the initiation of a new colony. In 12 of these genera females have a gland of ducted cells on sternite 5 (penultimate), associated with cuticular sculpturing of various types. Experimental or circumstantial evidence for several of these genera indicates that the product of this gland is used to lay an odor trail that guides the swarm from the parent nest to a new nest site. One genus has a similar gland on the sixth sternite, another has glands on both the fifth and the sixth, and the remaining six genera lack any evidence of sternal glands. The independent-founding species of Ropalidia have a sixth sternal gland associated with a tuft of setae, while the swarm-founding species have the tuft but lack the gland. Our interpretation of this is that the gland produces an ant repellent substance in the independent-founding species, but in the swarm-founding Ropalidia such a substance is of little value and so the gland has been lost.

Notes: Summary The flow of stained haemolymph was photographed in the wings of resting Pieris rapae, Pieris brassicae, and Gonepteryx rhamni under UV-radiation at definite intervals after abdominal application of fluorescent tetracycline. There is no circular route in the wing. All wing veins are supplied with stained haemolymph from their own bases without preference to single veins. In freely resting Pieris with intact wings, most veins are completely stained after 20 min. The staining pattern supports the existence of an oscillating haemolymph supply mechanism in the wing veins and shows that the cross vein and encircling sinus are not essential in the supply of the longitudinal veins. Inflow of stained haemolymph into the wing membrane begins about 1 h after application and is generally completed within 12 h in Pieris. The wing membrane is supplied with fluid by diffusion and — especially under low relative humidity — additionally by haemolymph substitution of evaporated water. This mechanism is associated with the disadvantages of water loss and probably salt withdrawal from the body. The puddling behaviour of butterflies might help in restoring these postulated deficits. It is hypothesized that haemolymph substitution of water evaporated from the wing membrane is a preadaptation for accumulation of defensive toxins and pheromones in the wing membranes, especially in diurnal and basking Lepidoptera. The veinal system of 5-day-old young summer specimens of Gonepteryx stains more intensely than that of 4–5-month-old specimens just before entering hibernation. The transition of stained haemolymph from vein to membrane is reduced in this species, probably as an adaptation for water retention during diapauses.

Notes: Summary The majority of large, bilaterally-symmetric animals possess two structurally distinct systems of internal fluid transport, the coelomic circulatory system and the blood vascular system (BVS). The coelomic circulatory system is generally situated laterally, lined by a continuous layer of mesodermally-derived cells and moves fluid with cilia or body wall muscles. The BVS occurs in extracellular matrix with the principal vessels situated dorsally and ventrally. The vessels are typically unlined by cells. Fluid is propelled by contraction of overlying muscle cells. Co-occurrence of two systems of internal fluid transport is explained by a segmentation hypothesis: Most large, triploblastic animals are segmented with at least two or three fluid-filled compartments separated by septal bulkheads. Because exchange surfaces (gas, nutrient) are regionally restricted, selective pressure favors a fluid transport system that bridges septal bulkheads. The BVS fulfills this requirement because it is situated in extracellular matrix that is non-cellular and continuous throughout organisms. A survey of animals indicates that all segmented taxa possess a BVS, except Sipuncula, where compensation sacs function as BVS analogues. Loss of the BVS in Hirudinea and other annelids is correlated with the disappearance of septa. Funicular vessels in Bryozoa are compared with BVS in other lophophorates. The fluid transport system of Nemertini and some platyhelminths is shown to conform to the definition of a coelomic circulatory system. This investigation supports Liwanow's proposition that the BVS evolved as the progressive modification of extracellular matrix in triploblastic animals. Evolution of coelomic circulatory systems is unresolved.

Notes: Summary Spermiogenesis and sperm cells of the meiobenthic priapulid Tubiluchus were described by means of the transmission electron microscope. The sperm cells are completely different from the male gametes of Priapulus, being elongated and thus indicating a different mode of sperm transfer. The anterior portion of the sperm head is characterised by a corkscrew configuration of nucleus and acrosome, both components being wrapped around each other. This kind of sperm cell has never been reported in other animal phyla.

Notes: Summary Freeze fracture preparations of the Branchiostoma epidermis revealed a number of specialisations of the plasma membrane. The highest number of intramembrane particles were found in the membrane of the microvilli, where they are predominantly localised in the P-face. In connection with the apical membrane an extracellular coat of complex branched filamentous structures (about 1.5 μm thick) can be demonstrated which was seen in carefully prepared transmission electron micrographs. In the area of the septate junction, the lateral plasma membranes are endowed with large numbers of variously sized membrane particles in the P-face which may form indistinct, short particle rows. The E-face is poor in particles. The freeze fracture image of this junction differs markedly from that of the mollusc-arthropod septate junction and bears similarities with the hemichordate and echinoderm septate junctions. Patches of particle aggregations suggest the presence of desmosomal contacts in the lateral membrane. No occluding or communicating junctions were found.

Notes: Summary An acoustic resonance technique has been evaluated as a means of detecting deterioration in wood poles. The basis of the technique is that degradation of the pole by rot or other agency will lead to an increase in the damping of longitudinal acoustic waves, which can subsequently be detected by an examination of the acoustic resonance characteristics of the pole. The technique was assessed in a series of field trials conducted on in-situ poles, which were subsequently removed and dissected. The results of the acoustic testing compared favourably with the gradings of the poles following dissection.

Notes: Summary Historically, adhesive development has been a propelling force in the evolution of the forest product industry. The 1973 energy crisis has caused the wood industry to focus its attention on the necessity of adhesive self-sufficiency. Research in the use of bark, pulp waste liquor and foliage for adhesive application is rapidly spreading. In addition, many new adhesives have been proposed by the chemical industry as alternatives for wood bonding. Recently developed physiochemical analytical methods have been successfully applied to this adhesive research area and to durability evaluation. However, there are still enormous difficulties in developing a durable natural product adhesive of low variability as well as a unified international interpretation of bond durability. Phenolic resins have weathered the energy crisis and are gaining importance in the industry. Some examples of recent contributions from phenolic-resin research to panel board and lumber end-joint developments will be discussed in detail.

Notes: Summary The fine structure of inactive eastern white spruce phellogen (Pg) and phelloderm is briefly described. Phellogen cells resemble dormant cambium but contain larger tannin vacuoles. Phelloderm cells contain even more tannin and have much thicker primary walls. Three types of phellem are described: crystalliferous phellem (CP), thin-walled phellem (TnP), and thick-walled phellem (TkP). All three occur in spruce, but only the latter two in balsam fir and eastern hemlock. The TnP cells have thin shared common walls overlain by suberinic and wax extractive layers. True pits are lacking, but plugged plasmodesmatal canals sealed over by the wax extractive layers cross the suberinic layers. Spruce CP and fir and hemlock TnP cells have adaxially-thickened suberinic and wax extractive layers when adjacent to TkP or inactive Pg. The suberin lamellae are much thickened in these suberinic layers, at least in spruce. Spruce CP has a thick wax extractive layer which also sheaths the crystals. The TkP cells of all three species have thick polylamellate abaxial cellin walls perforated by simple pits. The lamellae differ both in structure and composition. Polylamellate wall construction is discussed and a model proposed. The TkP cells have both suberinic and wax extractive layers in fir and hemlock, but only wax extractive layers in spruce. These cells are therefore true phellem cells, not phelloids.

Notes: Summary Deflections of wooden beams loaded repeatedly for seven or two days in every 14 were compared with those of beams under constant load over a period of six months in a constant environment. Four load levels were applied to beams of three species. Loads ranged from 17 to 67 per cent of short-time failing load estimated from matched specimens. The deflections under intermittent loads were lower than the creep deflections under constant load and, with the exception of material under high stress, applicability of Boltzmann's principle of superposition of deformations was confirmed. Non-linearity at high stresses is linked with other signs of weakening after application of loads in excess of about 50 per cent of short-time ultimate.

Notes: Summary A computerised wood densitometer system using X-rays is described. The technique uses 5 mm increment core samples, machined to 2 mm thickness in the axial direction of the fibre, and an isotopic radiation source (Fe 55). Direct measurement of the intensity of radiation passing through the sample enables wood density variations to be recorded automatically and stored on disc file for subsequent analyses with an interactive computer program.

Notes: Summary An equation is derived to describe transverse nonisothermal moisture movement in wood, based upon a gradient of chemical potential. When compared with a previously derived equation based upon a gradient of activated moisture molecules, this new equation predicts an accentuated effect of the thermal gradient relative to the moisture gradient at high wood moisture contents and a decreased effect at low moisture contents. The two equations yield identical results at a moisture content in equilibrium with a relative humidity of approximately 53 percent.

Notes: Summary The hypochlorous acid formed intermediately during the bleaching of an oxygen-prebleached kraft pulp with pure chlorine dioxide (a D0-stage) was captured as N-chlorosulfamic acid by addition of sulfamic acid to the bleaching liquor. The amount of hypochlorous acid captured corresponded to about 50 mol% of the consumed chlorine dioxide. The amount of chlorite formed (20 to 30 mol%) was less than the amount of hypochlorous acid captured. The excess of hypochlorous acid over chlorite suggests that chlorine dioxide is reduced initially not only by a one-electron mechanism to chlorite but also by a two-electron mechanism to monochlorine monoxide, which is then reduced by lignin or by chlorine dioxide to hypochlorous acid. The routes for the further reactions of chlorite, monochlorine monoxide and hypochlorous acid are discussed.

Notes: Summary Ultra-high pressure water jets, operating at 48 300 kPa through a ring-type No. 6 nozzle with 15° fan and 1.57 mm diameter opening, were used in practical trials for debarking several hardwood species. Eucalyptus paniculata, E. agglomerata, E. acmenioides, E. pilularis and Syncarpia glomulifera were tested, as they are known to be difficult to debark. The effects of these jets on the configuration of the detached bark, were also assessed. Except for E. pilularis, all species were effectively debarked, and a classification was made of the relative difficulty with which various barks were removed. In E. pilularis the bark adhered strongly to the timber, the surface of which was extensively damaged by the water jets. The high pressure water often broke and shattered the bark, which sometimes underwent pronounced defibration. In particular, the bark of E. acmenioides and E. paniculata was broken down into a material, which should be readily utilisable without further processing. Finally, these trials have shown that the design of a small-size hydraulic debarker is feasible and should eventually be a commercially viable proposition.

Notes: Summary The purpose of this study was to assess the relationship of oven-dry density, initial moisture content, vascular bundles and shrinkage to stem height and diameter of Cocos nucifera L. High correlations were obtained between initial moisture content and stem height, initial moisture content and oven-dry density, oven-dry density and stem height, vascular bundles per cm2 and stem height, vascular bundles and oven-dry density for cross-sections and shrinkage and vascular bundles per cm2. The high correlations between vascular bundles per cm2 and oven-dry density on the one hand and to shrinkage on the other can be used for visual grading of coconut timber.

Notes: Summary In the present paper a hydrothermolysis apparatus is described. The reaction vessel is of the percolator type with a volume of 560 cm3 and permits the hydrolysis of biomass materials up to 100 g. The optimum degradation conditions of pure cellulose (filter paper) were determined in dependence on temperature, flow rate of the eluting water and influence of stirring on the reaction mixture. Up to 52% glucose can be obtained by hydrolysing cellulose with pure water at 265°C at a flow rate of 12 cm3/min. Biomass materials such as poplar wood and wheat straw were hydrolysed in two stages, using temperatures of about 200°C for the easily hydrolysable polysaccharides and about 260°C for the polysaccharides, which are more difficult to hydrolyse. In the first stage on an average 45% of the initial amount is converted into soluble products, whereas in the second stage this value amounts to 48%.

Notes: Summary The use of ammonium sulfide in aqueous ethanol and methanol was investigated for pulping of wood. Hemlock chips required 21% ammonium sulfide (equivalent to 19% Na2O) at 180°C to become delignified to the kappa range 35–50. The yields exceeded those of conventional kraft pulps by 14% on dry wood basis. Over 75% of the original glucomannan was recovered in the pulp as the consequence of end group stabilization by ammonium sulfide. The intrinsic viscosity of the pulps, measured in cadoxen was 10.65 dl/g — approximately double the value for softwood kraft pulps. The pulps were readily bleached and possessed higher tensile and burst strengths but lower tear strengths than kraft pulps. Ammonium sulfide pulps from cottonwood were likewise obtained in high yields and with adequate strength properties.

Notes: Summary Changes in the submicroscopic porosity in southern pine latewood resulting from pyrolysis at temperatures through 600°C were measured using small-angle X-ray scattering. Two types of scattering curves were observed: the first was obtained for wood and for less intense heat treatment; and the second, for samples heated above 300°C. This change was found to be associated with the thermal degradation of crystalline cellulose in the sample. Specific surfaces and the average dimensions of macropores and micropores were calculated from the second type of scattering curve. The specific surface was found to increase from 1.2 to 2.3 m2/gm as the temperature and heating time increased. The average dimensions of the macropores calculated from the scattering curves was about 15 nm. The first effect of heating sufficiently to decompose the crystalline cellulose was found to be the production of micropores with average diameters of about 0.7 nm. Micropore volume increased from 0.06 cm3/gm for the lower heating temperatures to about 0.13 cm3/gm for samples heated to 600°C. The average micropore dimension increased as the temperature was raised and the samples were heated for longer times.

Notes: Summary In a typical sawmill, about 12% of the wood which is cut is reduced to sawdust. Further material is lost during subsequent planing. A substantial part of this large loss of a costly natural resource can be saved by the use of thin, stable sawblades, but only if proper saw tensioning conditions are developed. The thickness of a stable sawblade can be minimized through optimal tensioning, an increasingly urgent objective because of sharply rising raw material costs. A theoretical model is presented which accurately describes the development of residual stresses in a roll tensioned circular sawblade and the resulting changes in saw critical speed. This model is essential for the reliable prediction of optimal tensioning conditions for any given saw operating state, and for the development of automated control of the tensioning process. An example is presented of an optimally tensioned circular sawblade for which a 40% thickness reduction is achieved compared with an equivalent untensioned sawblade with the same critical speed.

Notes: Zusammenfassung In einem fur das Massenauftreten des Süßwasserpolypen Craspedacusta-sowerbii Lank. sehr günstigen Aquarium wurde ein ovales, aus dunklem Ektoderm und hellem Ektoderm bestehendes und mit etwa 14–16 Tentakeln ausgestattetes Gebilde gefunden. Nach 24 Std war daraus ein länglich wurstförmiges, sich wie eine „normale” Frustel fortbewegendes Stadium mit 8–12 verkleinerten Tentakeln geworden. Nach weiteren 10 Std hörte die Fortbewegung auf, die Frustel war kurz und breit und zeigte auch im Zeitrafferlaufbild nur noch geringfügige Kontraktionen. Nach Besprechung der Möglichkeiten wird als sebr wahrscheinlich angenommen, daß eine bis zum „Germanica”-Stadium entwickelte Meduse sich (in Parallele zum gleichen Vorgang beim Polypen) zurückbildete und dann sich zur Frustel umbildete. Ob die darauffolgende, nicht gelungene Umbildung zum Polypen auf ungünstige äußere Umstände zurückzuführen oder überhaupt nicht möglich ist, kann an einem einzelnen Exemplar nicht entschieden werden. Es wird die Vermutung ausgesprochen, daß die auf dem 8- and 16-Tentakelstadium sich befindenden „abortiven” Medusen nicht absterben, sondern sich rückzubilden imstande sind.

Notes: Zusammenfassung Die Fauna des Strandanwurfs ist durch zwei große Freilanduntersuchungen gut bekannt. Dieser Lebensraum läßt sich im Labor leicht und jederzeit reproduzieren. Daher erschien er zu einem Vergleich der experimentell-ökologischen Methode mit den Freilandergebnissen besonders geeignet. An Stelle einer großen Zahl von Arten werden nur einige wenige charakteristische Formen ausgewählt, these aber über mehrere Generationen gezüchtet. Alle Arten sind Schwankungen der Umweltverhältnisse gegenüber sehr unempfindlich und vermögen ungünstige Perioden lange zu ertragen. Für den Ablauf des gesamten Individualzyklus sind dagegen ganz spezielle Bedingungen erforderlich. So sind — für die Vollendung des Individualzyklus — alle Arten an spezielle Salzgehaltswerte in der Nahrung gebunden, an bestimmte Temperaturen, an bestimmte Nahrungsarten und an bestimmte Feuchtigkeit. Die meisten Arten sind ferner an ungünstige Verhältnisse, wie she im Strandanwurf als einem meeresnahen Lebensraum auftreten, besonders angepaßt. Sie ertragen Überflutungen, Überlagerungen mit Sand und hohe Windgeschwindigkeiten besser als nahe verwandte oder ähnliche Tiere des Binnenlandes. Dabei zeigen sie oft spezielle Verhaltensweisen. Die Mechanismen, nach denen die Tiere des Anwurfs ihr Milieu finden und erkennen, werden untersucht. Wahrscheinlich spielt astronomische Orientierung eine wichtige Rolle, wenn auch bisher nur eine Art untersucht wurde. Bei der Eiablage, die stets auf Plätzen erfolgt, die für die Larve günstige Entwicklungsmöglichkeiten bietet, orientieren sich die Imagines der Fliegen sehr genau nach der Größe der betreffenden Stelle, dem Salzgehalt and der Nahrungsart. Die Ergebnisse zeigen, daß Resultate von Laborexperimenten durchaus ins Freiland übertragen werden dürfen. Es müssen aber langfristige Zuchtversuche angestellt werden, nicht nur kurzfristige Experimente. Diese liefern häufig Ergebnisse, die nicht ins Freiland übertragen werden dürfen. Die experimentelle Ökologie kann keine ökologischen Artdiagnosen geben, sondern nur die Mechanismen der Umweltbindung, der Orientierung, der Konkurrenz and des Parasitismus studieren.

Notes: Zusammenfassung Es werden ökologische Beobachtungen über die Abhängigkeit der geographischen Verbreitung der Terediniden, holzbohrenden Crustaceen und Balaniden von den hydrographischen Verhältnissen, die am jeweiligen Fundort herrschen, am Beispiel der für derartige Untersuchungen ganz besonders geeigneten Lagune von Venedig mitgeteilt. Ausführliche Verzeichnisse der zahlreichen, vom Verf. zu wiederholten Malen in den letzten Jahren besuchten Fundstellen der genannten Tiergruppen an den Lagunenpfählen erlaubten die Berechnung der ungefähren Häufigkeit der betreffenden Arten in der gesamten Lagune von Venedig sowie in einzelnen Abschnitten derselben. Dabei stellte sich die Tatsache heraus, daß die Verteilung dieser Tiere im Lagunenraum in unmittelbarer Abhängigkeit von den zum Teil recht verschiedenen hydrographischen Faktoren (Salzgehalt, Temperatur, Gezeitenströmungen, Windrichtungen usw.) steht. Auf Grund der lagunaren Verbreitung lassen sich unschwer Steno- und euryhaline Arten erkennen, und auch die interessanten Beziehungen zwischen Temperatur und Fortpflanzungszeiten sind, wie dies besonders für die Terediniden gezeigt wird, von ausschlaggebender Bedeutung für das Vorkommen der Arten nicht nur im begrenzten Raum der Lagune sondern im freien Meere überhaupt. Tabellarische Übersichten über die tiergeographisch wichtigen biologischen Daten der untersuchten Tiere und über die örtlichen hydrographischen Gegebenheiten erläutern im einzelnen die ökologischen Voraussetzungen für das Vorkommen oder Fehlen der jeweiligen Arten.

Notes: Zusammenfassung 1. Die symbiontischen Einrichtungen von 32 Fulgoroiden-Arten wurden untersucht. Der Hauptanteil der untersuchten Arten entfällt auf die Familie Araeopidae (26 Arten). Die übrigen Arten gehören zu den Familien Cixiidae (3), Tropiduchidae (1) und Issidae (2). 2. Alle untersuchten Arten beherbergen Symbionten. 20 Arten sind disymbiont, 11 Arten sind trisymbiont, eine Art ist tetrasymbiont. 3. Von den Symbionten der untersuchten Arten waren drei Bakterienformen noch nicht beschrieben: Ein akzessorischer Symbiont im a-Organ von Trypetimorpha fenestrata (AT-Symbiont) und zwei Begleitsymbionten bei Arten der Gattung Kelisia (q1- und q2-Symbionten). 4. Die von früheren Autoren eingeführte Gliederung der Symbionten in Haupt-, Neben-, Begleit- und akzessorische Symbionten spiegelt nicht das Alter der Symbionten wider, sondern nur deren Verbreitung und die Wechselbeziehungen mit anderen Symbionten. 5. Die a-, x- und f-Mycetome sind innerhalb der gesamten Fulgoroiden homolog. Die Besiedelung des Fettgewebes durch Hefen kann nicht homologisiert werden. 6. Von Conomelus limbatus (Symbiontenkombination H+f) und Stenocranus minulus (Symbiontenkombination a |− x + q) wurde die Embryonalentwicklung der symbiontischen Einrichtungen untersucht. Besondere Aufmerksamkeit galt dem Verhalten der verschiedenen Symbionten während der Eientwicklung. 7. Die Embryonalentwicklung der symbiontischen Einrichtungen verläuft in sechs Hauptstadien. Innerhalb dieser Etappen werden die verschiedenen Symbionten (a, x, q, H) vom Wirt nicht gleichartig behandelt. Unterschiede zwischen den Symbionten zeigen sich vor allem im Stadium der Symbiontensonderung und während der Differenzierung der definitiven Symbiontenorgane. 8. Aus den Unterschieden in der Behandlung der Symbionten durch den Wirt während der Embryonalentwicklung lassen sich Schlußfolgerungen auf das Alter der Symbionten ziehen. 9. An Hand der Ergebnisse wurde die Verwendbarkeit symbiontischer Einrichtungen zur Rekonstruktion der Phylogenese der Fulgoroiden untersucht. Die Rekonstruktion der Phylogenese der Fulgoroiden führt zu einem monophyletischen Stammbaum. 10. Die Ergebnisse der vergleichend-anatomischen und embryologischen Untersuchungen zeigen, daß die a-Symbionten die ältesten in Fulgoroiden lebenden Mikroorganismen sind (Bestätigung der Ansichten von H. J. Müller 1951).Ihnen folgen die x-Symbionten und die f-Symbionten. Diese Symbiontenkombination (a + x + f) bestand vermutlich schon vor der Aufsplitterung der Fulgoroiden in die rezenten Familien (Ausnahme = Tettigometridae eventuell Laternariidae). 11. Die Hefen können nur als junge Symbionten gelten. Sie sind von verschiedenen Familien unabhängig erworben. 12. Die Entwicklung der rezenten Symbiontenkombinationen der Araeopiden aus der Kombination a + x + f wird diskutiert. Die Kombination a + x + f zerfiel in die Kombinationen a + x und x + f, die zu den Ausgangskombinationen getrennter Entwicklungsreihen (a- und f-Reihe) wurden. Analog wurden in beiden Reihen neue Symbionten in die Ausgangskombinationen aufgenommen. In der f-Reihe führte die Aufnahme der Hefen zur Elimination bereits vorhandener Symbionten (x, vermutlich auch r), nur die f-Symbionten wurden nicht verdrängt.

Notes: Zusammenfassung 1. Die Laubheuschrecken sind monostroph linksflügelig. 2. Eine Asymmetrie der Vorderflügelflächen männlicher Laubheuschrecken wird festgestellt und statistisch gesichert. Der linke Vorderflügel ist flächenmäßig größer. Bei weiblichen Tieren kann kein Unterschied nachgewiesen werden. 3. Eine Asymmetrie des Gewichtes der Vorderflügel männlicher Laubheuschrecken wird ermittelt und statistisch gesichert. Der linke Vorderflügel wiegt wesentlich mehr als der rechte. Die Vorderflügel weiblicher Laubheuschrecken zeigen keine Gewichtsasymmetrie. 4. Die Vorderflügel männlicher Laubheuschrecken zeigen in ihrer Aderung eine deutliche R/L-Asymmetrie. 5. Die Schrilleiste auf dem rechten Vorderflügel männlicher Laubheuschrecken ist schwächer ausgebildet als die auf dem linken Vorderflügel. Die Unterschiede in der Anzahl der Schrillzähnchen werden statistisch gesichert. 6. Der linke Vorderflügel männlicher Laubheuschrecken ist im Dorsalteil stärker pigmentiert als der rechte. Bei weiblichen Tieren lassen sich nur geringfügige Unterschiede hinsichtlich Flügelfärbung feststellen. 7. Bei Schrillversuchen mit männlichen Laubheuschrecken zeigt sich, daß eine künstlich herbeigeführte „verkehrte Lage” der Elytren meist korrigiert wird. Eine Tonerzeugung ist, von Ausnahmefällen abgesehen, durch das Fehlen einer Bewegungskoordination unmöglich. 8. Zur Erklärung der Entstehung minimaler Erbunterschiede an den Flügeln von Laubheuschrecken reicht die klassische Mutations-Selektions-Theorie aus; sofern man zusätzlich den von Ludwig als Geoffroyismus, von anderen Autoren als „Baldwineffek” bezeichneten Mechanismus hinzuzieht.

Notes: Zusammenfassung 1. Bei einem morphologischen Vergleich der Imagines und Entwicklungsstadien von A. bilineata Gyll. und A. bipustulata L. konnten eindeutige Unterschiede nur zwischen den Imagines einerseits und dem 1. Larvenstadium andererseits gefunden werden. Prinzipielle Unterschiede in der Biologie beider Arten bestehen nur in der Dauer der Gesamtentwicklungszeit. Damit steht im Zusammenhang, daß A. bipustulata im Jahr in 3 Generationen erscheint, während A. bilineata nur 2 Generationen ausbildet. 2. Es werden Beobachtungen über das Verhalten der Imagines im Freiland und in den Laborzuchten mitgeteilt. Unter anderem konnte endgültig nachgewiesen werden, daß die Imagines keine vollentwickelten Puparien angreifen. Das Paarungsverhalten wird beschrieben. Weiterhin wurden die Größe der Nachkommenschaft und die Lebensdauer der Imagines jeder Art ermittelt. 3. Die Dauer der Eientwicklung von A. bilineata in Abhängigkeit von der Temperatur wurde näher untersucht. Die untere Entwicklungsgrenze lag zwischen 10 und 11° C, die obere zwischen 32,5 und 35° C. Die Eier nehmen 12–24 Std nach der Eiablage Wasser auf. Dieser Vorgang ist nach weiteren 24–36 Std abgeschlossen. Für den Larvenschlupf aus dem Ei wurde die Bedeutung der Chitinhöckerpaare auf dem Metathorax und dem 1. Abdominalsegment als Eizähne erkannt. 4. Das I. Larvenstadium besitzt ein Pygopodium, das sowohl für die Fortbewegung als auch als Haftorgan beim Nagen des Loches in der Pupariumwand eingesetzt wird. Innerhalb des Pygopodiums konnten ventral an der Haftfläche Drüsen gefunden werden, deren Sekrete wahrscheinlich die Haftwirkung erhöhen. Das I. Larvenstadium nimmt Feuchtigkeitsunterschiede wahr. Hindert man es an der Nahrungsaufnahme, so sind bei 22° C die Reservestoffe nach 3–5 Tagen aufgebraucht. Der Kot wird im Enddarm gespeichert und his zum Hungertod nicht nach außen abgegeben. Während des Hungerns erfolgt eine Umstimmung im Bewegungsverhalten des 1. Larvenstadiums. Nach Laborversuchen zu urteilen, ist dieses Stadium nicht in der Lage, die Kohlfliegenpuparien im Boden über eine größere Entfernung hinweg gerichtet aufzufinden. Das Eindringen des 1. Larvenstadiums in ein Puparium wind beeinflußt durch Bodenfeuchtigkeit, Entwicklungs- und Parasitierungszustand des Pupariums. Durch genaue Lochkartierung wurde festgestellt, daß die meisten Locher auf dem 4., 5. und 6. Dorsalabschnitt angelegt sind, da unterhalb dieser 3 Pupariumabschnitte sich der größte zusammenhängende Hohlraum befindet. Die Ursache für das Abweichen von der Regel bei der Ortswahl des Loches ist in dem Konkurrenzverhalten der Larven zu sehen. Die in ein Puparium eingedrungene Larve verschli\ßt hinter sich mit dem gespeicherten Kot ihre Einschlupföffnung. Sie ist in der Lage, auch noch weitere Löcher auf these Weise zu verschließen. Die Diapause des 1. Larvenstadiums von A. bilineata wird durch die Diapause der Fliegenpuppe ausgelöst. 5. Die Art der Nahrungsaufnahme der 3 Larvenstadien wurde analysiert. Danach wird der Inhalt der Fliegenpuppe durch die Larven ausgedr\:uckt. Vom Beginn der Nahrungsaufnahme bis zu deren Ende werden von den 3 Larvenstadien keine Stoffwechselendprodukte durch den After nach au\sBen abgegeben. Diese Stoffe werden in den Malpighischen Gef\:a\sBen und in einer Erweiterung des Enddarmes gespeichert. Das 3. Larvenstadium scheidet in 3 Phasen die Exkrete aus. 1. Phase: Abgabe einer wasserklaren Fl\:ussigkeit, die durch zahlreiche zu diesem Zeitpunkt von der Larve in die T\:onnchenwand genagte schlitzf\:ormige \:Offnungen nach au\sBen sickert. 2. Phase: Der Kot wird gleichm\:a\sBig \:uber die ganze T\:onncheninnenwand verteilt. 3. Phase: Die Produkte aus den Malpighischen Gef\:a\sBen werden durch den After, \:ahnlich einem Spinnvorgang, ebenfalls an die Tonncheninnenwand abgeschieden. Die hohe Mortalität des 3. Larvenstadiums von A. bipustulata in größeren Kohlfhegenpuparien erklärt sich mit der Tatsache, daß dieses Stadium dal für lie zu reiche Nahrungsangebot nicht bewältigen kann, vorzeitig mit der Exkretion beginnt and durch die in Zersetzung übergehenden Nahrungsreste abstirbt. 6. Wie aus Versuchen und Beobachtungen hervorgeht, ist den Aleochara-Arten eine die Massenvermehrung der Kleinen Kohlfliege einschr\:ankende Wirkung nicht abzusprechen. Es werden Vermutungen \:uber die m\:oghche Entwicklung des Parasitismus innerhalb der Gattung Aleochara ge\:au\sBert.

Notes: Summary The viscoelastic deflection resulting from load increasing continuously from 30% stress level (linear range) to 60% stress level (non-linear range), i.e., within the proportional limit was measured over a period of 10 h. The experimental deflection could be predicted by a numerical method using model element constants which were an experimentally determined function of stress level. An 8-element model consisting of a Maxwell model and three Voigt models in series was used. The upper limit of stress level where a linear relation between creep strain and stress holds ranged from about 35% to 40%. Calculated deflections agreed well with experimental deflections.

Notes: Summary Two equations are derived to describe the nonisothermal unsteady-state diffusion of moisture in one direction in parallel-sided bodies. One equation is based upon a gradient of activated moisture molecules and the other on a gradient of chemical potential.

Notes: Summary A coarse thermomechanical Asplund pulp was prepared from Norway spruce (Picea abies). The pulp was delignified to different degrees using acidified sodium chlorite. The swelling behavior (measured as water retention value=WRV) of the resulting pulps was studied under various chemical conditions (pH and conc. of NaCl). It is shown that chlorite-delignified pulps have an appreciable polyelectrolytic character. Whereas the WRV of an Asplund pulp does not respond to changes in the chemical environment, the delignified pulp has a WRV of 155 at pH 3 and 250 at pH 9. Compared under the same chemical conditions, the WRV increases with increasing degree of delignification (〈70%) and is approximately constant at high degrees of delignification (〉70%).

Notes: Summary Morphactin IT3456, applied in a 2–3 cm band around the middle portion of 2- or 3-year-old internodes of artificially inclined 5-year-old Japanese larches, induced compression wood formation on both the upper and the lower sides of the inclined stem above the treated region, while it inhibited compression wood formation below this region. These results seem to suggest that a high concentration ratio of endogenous auxin to sugar (auxin/sugar) in the differentiating xylem tissue is necessary and sufficient for compression wood formation, and that compression wood formation under natural conditions requires polar transport of auxin which supplies and maintains high concentration of auxin along the undeside of the stem.

Notes: Summary The autoxidation kinetics of vanillin (4-hydroxy-3-methoxy benzaldehyde) have been investigated in aqueous media between pH 5.0 and 13.5. The results obtained clearly show two distinct reaction mechanisms are operative. At pH 7.3 the reaction orders with respect to vanillin concentration and oxygen partial pressure are 1.50 and 0.5 respectively, indicative of a free-radical chain process. A bimolecular ionic pathway is indicated at pH 11.0 and above since the reaction orders with respect to both vanillin and oxygen are 1.00. The formation of a hydroperoxide intermediate is believed to be the first step in both pathways. The energy of activation was found to be 14.2 kcal/mole at pH 7.3 and 13.6 kcal/mole at pH 11.0.

Notes: Summary The high potential of marketing dry wood encourages the study of the possibility to kiln dry green hardwood. Description of the technical details of three drying processes and their differences are discussed. One of the processes is recently developed, and is called “Continuously Varying Schedule”. Three drying tests were carried out using each process to dry green 100×50 mm quarter and back sawn Eucalyptus laevopinea and E. agglomerata. The Continuously Varying Schedule and the Continuously Rising Temperature processes reduced the drying time to one third that of the Conventional process. Recovery in volumetric shrinkage for samples dried by the Continuously Varying Schedule was not significantly different from those dried by the conventional Schedule, but different at the 5% confidence level from those dried by the Continuously Rising Temperature.

Notes: Summary Some aspects of sulphur-free soda pulping with anthraquinone (AQ) additions and chlorine-free bleaching with oxygen-based treatments were investigated with the aim of producing bleached softwood pulp with kraft-like strength properties. The extent of soda-AQ pulping was studied by pulping to 32, 42 and 68 Kappa number. After oxygen delignification to 10, 15 and 20 Kappa number respectively, the extent of bleaching with ozone, alkali extraction, and hydrogen peroxide treatments (ZEP sequence) was studied. For comparison, oxygen delignified pulps were conventionally bleached with a sequential chlorine/chlorine dioxide, alkali extraction, and chlorine dioxide (D/CED) sequence. A reference kraft pulp at 45 Kappa number was similarly oxygen delignified and bleached. Kraft-like strength properties (as measured by tear/burst relationships) were attainable if soda-AQ pulping was terminated at high Kappa number and was followed by oxygen delignification and D/CED bleaching. This pulp had a 3% (on wood) higher total yield and consumed less active alkali (2.0% as Na2O) than the bleached reference kraft pulp. Soda-AQ pulping followed by oxygen delignification and ZEP bleaching produced pulp with strength properties that were at least 25% less than those of the reference kraft pulp after oxygen delignification and conventional bleaching with chlorine-based treatments. Although the combination soda-AQ pulping to low Kappa number and extended oxygen delignification adversely affected pulp strength properties, it was ZEP bleaching and ozone treatments in particular, which caused the majority of the strength loss.

Notes: Summary The permeability to water of the cell wall has been measured by applying a known osmotic pressure generated by PEG 6000 across wood samples containing water-swollen cell walls. In pine the void space was filled with silicone resin with the wood at near fibre saturation point. Permeability kx1021 as defined by the Darcy equation was 37.9 m2 for longitudinal flow and 0.96 m2 for tangential flow. Tangential permeability was also measured using water-saturated samples of spruce and lime, and allowance was made for the very high permeability of the water-filled cell cavities. The results were in satisfactory agreement with values obtained previously using wood filled with wax or resin. The variation of tangential permeability with temperature was measured over the range 10–55°C for pine and lime. The activation energy for flow through the cell wall was 6.8 kcal/mole for pine and 5.3 kcal/mole for lime. These values are much higher than the activation energy for viscous flow of water, presumably owing to hydrogen bonding of the water to the cell wall material.

Notes: Summary Viscoelastic bending loads resulting from prescribed deflections increasing continuously or stepwise from 0, 20, or 30% initial stress level (linear range) to 55 or 65% final stress level (non-linear range), i.e., within the proportional limit, were measured over a period of 10 h. Loads could be predicted by a numerical method using model element constants which were an experimentally determined function of deflection. An 8-element model consisting of a Maxwell model and three Voigt models in series was used. The upper limit of stress level where linear relation between creep strain and stress holds ranged from about 35 to 45%. Calculated load changes agreed well with experimental load changes.

Notes: Summary Round wood wafers, 4 mm thick along the grain and 2 cm in cross-sectional diameter, of green basswood (Tilia americana L.), yellow birch (Betula alleghaniensis Britton), and black cherry (Prunus serotina Ehrh.), were dried to equilibrium in air of 77% relative humidity and 25°C. Weight, and radial and tangential dimensions were recorded during the drying using a mean air velocity of 212 feet/minute. Two drying stages were observed, a constant rate period during the early stages, followed by a falling rate period. The convective heat transfer coefficient h calculated from the constant drying rate period and based on an energy — mass balance equation was about 6.1×10-4 cal/cm2-sec-C° (4.5 BTU/ft2-hour-F°). It was independent of wood species and was within the range found by other workers. The calculated emission coefficient σ ranged from 0.50 to 0.58×10-4 cm/s. From the dimensional change measurements, it was noted that radial shrinkage began later than tangential shrinkage in each specimen tested. This may be due to structural differences between ray and longitudinal tissues.

Notes: Summary Inherent in most simulation processes is a mechanism to sample from known probability distributions. This is most often accomplished with the aid of pseudo-random generation systems. Though, these generators produce sets of numbers which are usually statistically indistinguishable from a uniform distribution, the actual distribution of any individual one of these data sets exhibit peaks and valleys which, when used in simulations, somewhat misrepresent the desired probability distribution. A stratified approach to fulldistribution sampling is presented which represents a marked improvement over random number generated sampling in certain types of simulation procedures.

Notes: Summary Round wood wafers, 4 mm thick along the grain and 2 cm in cross-sectional diameter, of green basswood (Tilia americana L.), yellow birch (Betula alleghaniensis Britton), and black cherry (Prunus serotina Ehrh.), and initially dried to equilibrium in air of 77% relative humidity and 25°C, were exposed to sinusoidally varying relative humidity between 77 and 47% at 25°C for many cycles at each of four different cycling periods, 5.33, 10.67, 16.0 and 25.33 hours. Moisture changes and radial and tangential dimensional changes in response to the imposed humidities, measured during initial drying and subsequent cycling, gave the following results: 1. The moisture and dimensional changes were generally sinusoidal but lagged behind the imposed humidity. The phase lag decreased and the amplitude increased with increasing cycling period. Both responses and phase lags approached repetitive or “steady-state” values as cycling was prolonged. 2. A numerical solution for moisture diffusion, assuming a constant diffusion coefficient and sinusoidally varying boundary moisture conditions, was used to simulate the average moisture content in the wafer at any time. The resulting curves were qualitatively similar to those obtained experimentally, the differences attributed primarily to the effects of hysteresis and stress relaxation. 3. The mean moisture diffusion coefficients, calculated from steady-state phase lag data combined with an analytical solution of the diffusion equation, decreased with increasing cycling period. The values obtained increased with decreasing wood specific gravity as anticipated, but their magnitudes were somewhat lower than theoretical values. 4. The dynamic moisture expansion coefficient was relatively constant during successive cycles, with no consistent effect of cycling period. The dynamic values were generally higher than the static values. 5. The dynamic humidity expansion coefficient increased with increasing cycling period. It was only about half that obtained from static experiments, presumably because of hysteresis. 6. The dynamic moisture sorption coefficient, which is the effective slope of the dynamic sorption isotherm, decreased with increasing number of cycles and decreasing cycling period. It was less than half the calculated static sorption isotherm in the same humidity range, presumably due to hysteresis.

Notes: Summary Three parameters have been found to be important to the long-term effectiveness and durability of CCA-treated timber: (i) the temperature during treatment, (ii) the initial pH of the CCA solution, and (iii) its concentration. Variation in the values of these parameters cause drastic differences in the distribution between lignin and holocellulose of the preservative chemicals, in particular of the chrome and of the part of copper and arsenic reacted with it. The massive differences in distribution which are obtainable will considerably affect the durability of CCA-treated timber. It is clear that the effectiveness of CCA types A, B and C is valid only within narrow limits of the parameters mentioned. New, more effective and more economical CCA formulations, both in chemical composition and requiring lower loads (Softwoods), in the timber without a drop in the durability of the treated timber can be devised from the results presented, as well as more rapid and economical timber treatment processes. CCA formulations giving better soft-rot resistant hardwoods can also be devised.

Notes: Zusammenfassung 1. Am Gehirn von Larven und Imagines der Schabe Periplaneta americana wurden Exstirpationen von Zellgruppen und Durchtrennungen von Faserzügen vorgenommen und die sich daran anschließenden degenerativen und regenerativen Prozesse untersucht. Dabei wurden auch die Veränderungen im Verhalten der operierten Tiere geprüft, und die Abweichungen im Hormonhaushalt als Folge der partiellen oder völligen Entfernung der neurosekretorischen Zellen des Hirns durch die Operationen studiert. 2. Nach medianer Hirndurchtrennung fand bei Larven und Imagines innerhalb von 2–3 Wochen eine Regeneration von Nervenfasern statt, wenn die Zellkörper erhalten geblieben waren. Das Faserwachstum war bei den Larven stärker als bei den Imagines. Eine Lenkung der regenerierenden Fasern ließ sich nur bei der optischen und olfaktorischen Kommissur feststellen. Die Folge dieser Operation war ein gesteigerter Erregungszustand der Tiere, der sich besonders in ungehemmtem Fressen äußerte. Die Ursache dieser Enthemmung ist in der Verletzung des Zentralkörpers zu suchen. Nach dessen Regeneration gingen die Symptome zurück. Der Erregungsweg für die Fühlerputzbewegung wurde ermittelt. 3. Die einseitige Abtrennung des Tritocerebrums konnte durch Regeneration wieder behoben werden. Die durch diesen Eingriff hervorgerufene Manegebewegung ging mit der fortschreitenden Faserregeneration völlig zurück. 4. Nach Abtrennung der Lobi optici bei Larven und Imagines wurde allmählich die Verbindung zwischen Hirn und Lobi optici wiederhergestellt. Gesichert wurde dieser morphologische Befund durch den Nachweis optomotorischer Reaktionen. Nach einseitiger Regeneration der Lobi optici trat bei den Tieren keine Manegebewegung auf. Isolierte Teile des Nervensystems kugelten sich in der Kopfhöhle ab. Vom Zentralorgan isolierte sensorische Projektionsgebiete (Lobi optici) blieben noch längere Zeit erhalten. Zu ihrer dauernden Erhaltung bedürfen sie aber einer Verbindung zum Zentralorgan. 5. Ein- und beidseitige Becherexstirpation bei Imagines führte zum degenerativen Abbau des Stielsystems der Corpora pedunculata. Ein Ersatz der entfernten Strukturen erfolgte nicht. Die Wundfläche wurde durch ein Pseudoepithel aus Lymphocyten abgeschlossen. 6. Die gleichen Operationen riefen bei Larven nach 40–60 Tagen einen Ersatz der Becherstrukturen durch große, plasmareiche Zellen von der Hirnvorder- und -rückseite hervor, die durch dorsales Aus wachsen unter Volumenvergrößerung und wahrscheinlich auch durch Zellvermehrung von, Glia- und Perineuriumgewebe innerhalb von 2–3 Häutungen den frei gewordenen Raum ausfüllten. Eine Wiederherstellung der ursprünglichen Strukturen wurde nicht beobachtet. 7. Tiere mit einseitig entfernten Bechern zeigten kein verändertes Verhalten. Nach beidseitiger Exstirpation der Becher war eine Verringerung der spontanen Aktivität der Tiere festzustellen. Das Paarungsverhalten ist bei P. americana nicht an die Funktionsfähigkeit der C. ped. gebunden. 8. Spezifische, z. T. sehr große Zellen in der Pars intercerebralis konnten durch ihr Aussehen und die nach ihrer Exstirpation auftretenden Veränderungen in der Struktur der C. all. und C. card. als neurosekretorische Zellen erkannt werden. Sie sind offenbar den C. all. und C. card. übergeordnet. Die Verbindung dieser n. s. Z. zu den genannten Hormondrüsen zeigte keine Überkreuzung der Nervi Corp. card. I. 9. Die völlige Ausschaltung der n. s. Z. unterbrach bei den Larven den Entwicklungsablauf, worauf die Tiere eingingen. Teilweise Exstirpation zu verschiedenen Zeitpunkten der Zwischenhäutungsphasen bewirkte Abweichungen im Häutungsablauf und das vorzeitige Auftreten imaginaler Strukturen bei Larven. 10. Beiderseitige Exstirpation der n. s. Z. bei Imagines hatte eine Steigerung der parthenogenetischen Kokonablage zur Folge. Die damit verbundene Auszehrung der Tiere und Veränderung der C. all.-Struktur läßt auf eine Beeinflussung des gesamten Stoffwechsels schliesßen. 11. Eine einseitige Enthirnung bei Larven lehrte, daß aus nichtnervösem Zellmaterial kein Ersatz von nervösen Strukturen erfolgen kann und daß zur Erhaltung und Regeneration eines Sinnesorgans eine Verbindung zum Zentralnervensystem erforderlich ist. Regenerierte Fühler konnten bei Ausfall des gleichseitigen sensorischen Projektions-gebietes auch nach Verbindung mit dem gegenseitigen Projektionsgebiet wieder funktionsfähig werden. 12. Der Ersatz von Ganglienzellen des Hirns bei Erhaltung ihrer Bildungszentren kann wohl weitgehend als eine Fortsetzung bzw. Vorwegnahme des normalen Entwicklungsablaufes angesehen werden und nicht als typische Regeneration.

Notes: Zusammenfassung l. Die Mandibeldrüse vonTrigona scaptotrigona erzeugt ein Duftsekret, das bei der Alarmierung verwendet wird. Die anatomischhistologischen Verhältnisse dieser Drüse werden untersucht; sie besteht aus einem einschichtigen Drüsenepithel und ist vom Schlüpfen bis zum Tode der Tiere funktionsfähig. Die Zellen sind vom Typ der Ampullendrüsenzellen, in denen ein gewundenes Röhrchen liegt, das das Sekret in das Drüsenlumen leitet. 2. Nach Abgabe von größeren Mengen des Sekretes werden in den Drüsenzellen rasch die Vorstufen desselben mobilisiert und frisches Sekret abgesondert, so daß nach etwa 20 min wieder größere Mengen vorhanden sind. 3. Die Mandibeldrüse derApis-♀ ist beim Schlüpfen noch außer Funktion; sie erfährt ihre stärkste Entwicklung zur Zeit des Hochzeitsfluges. Messungen an Drüsenzellen, Deutung des histologischen Bildes der Drüse und verschiedene Versuche führen zur Annahme, daß sie beim Hochzeitsflug als Duftorgan zur Anlockung der ♂♂ wirkt. 4. Entfernung der Mandibeldrüse an lebendenApis-♀♀ zeigte, daß die Tiere geraume Zeit ohne diese Drüse leben können, sogar Eier legen und im Stock weiterhin als Königinnen anerkannt werden. Es ist daher in Frage gestellt, ob in der Mandibeldrüse die „Königin-Substanz” erzeugt wird. 5. Die Mandibeldrüse der Apiden, sowohl der ♀ als auch der , ist mit einem Verschlußmechanismus ausgestattet, so daß das Sekret nicht automatisch beim Spreizen der Mandibeln austritt, sondern nach Bedarf abgegeben werden kann. Es liegt sogar ein besonderes Feld von Chemorezeptoren unter der Drüsenmündung, das die Abgabe des Sekretes zu kontrollieren vermag. Demzufolge müssen verschiedene Meinungen bezüglich der Funktion der Drüse — insbesondere beiApis — revidiert werden. 6. Die Mandibeln der Honigbiene sind hochspezialisierte Werkzeuge, die mit verschiedenen Sinnesorganen ausgestattet sind: wir finden Tangorezeptoren, die besonders bei der zu Hilfsorganen angeordnet sind, und Chemorezeptoren, die den Nektar beim Saugakt geschmacklich prüfen und das Mandibeldrüsensekret beim Austreten wahrnehmen. 7. In den Mandibeln der Mehponiden und Hummeln befinden sich Ampullendrüsenzellen — Intramandibel-Drüsen — deren Ausführungs-kanälchen an der äußeren Wand der Kiefer münden; ihre Funktion ist noch unbekannt. 8. Untersuchungen an mehreren Familien von Apiden zeigten, daß phylogenetisch die Mandibeldrüse als erste Kopfdrüse auftritt. Bei den primitiven Arten ist sie noch klein und einfach gebaut, in einigen hoch entwickelten Bienen-Arten dagegen groß und kompliziert; sie erzeugt aber in allen Familien Duftstoffe, die entweder von den ♂♂ a oder von den ♀♀ zur Paarungszeit oder von den bei der Alarmierung verwendet werden.

Notes: Zusammenfassung 1. Eihüllsekrete der Insekten sind Drüsenabsonderungen der mütterlichen Imago, welche die abgelegten Eier vollkommen oder teilweise bedecken und einen direkten oder indirekten Schutz für sie darstellen. 2. Unter den einheimischen Cercopiden konnten bisher Eihüllsekrete auf den Gelegen nur beiPhilaenus, Neophilaenus undLepyronia nachgewiesen werden. Literaturangaben über eine Sekrethülle der Eier vonAphrophora salicina beruhen auf einer Fehlbeobachtung.Aphrophora salicina versenkt ihre Eier in junge Zweigspitzen vonSalix, die sekundär welken (bisher widersprechende Literaturangaben).Aphrophora alni belegt erdnahe Stengelteile krautiger Pflanzen, wobei welkes Gewebe bevorzugt wird.Cercopis sanguinolenta undCercopis sanguinea legen in basale Teile krautiger Pflanzen ab. Der vordere Eipol der in das Gewebe krautiger Pflanzen versenkten Eier vonLepyronia coleoptrata ist mit einem schaumigen Eihüllsekret bedeckt. Bei den Cercopiden, die ihre Eier in Spalträume ablegen und mit einem schaumigen Sekret bedecken, bestehen hinsichtlich der Quantität der Sekretmasse inter- und intraspezifische Differenzen. 3. Aus vergleichend anatomischer und histologischer Betrachtung der Gonodukte, ihrer Anhangsgebilde einschließlich der akzessorischen Genitaldrüsen sowie der Verfolgung der Ontogenie dieser Organe während der Imaginalentwicklung und aus den Ergebnissen von Exstirpations-experimenten ergibt sich, daß bei den Cercopiden die Eihüllsekrete in der unpaaren medianen akzessorischen Genitaldrüse gebildet werden. 4. Diese tubulöse mediane Drüse ist bei allen (heimischen) Cercopiden vorhanden. Ihre Sekretionsintensität und Größe entsprechen den Befunden der Eigelege. Arten, bei denen auf den Eiern kein Sekret nachgewiesen werden konnte, sezernieren äußerst gering. 5. Die mediane Drüse wird während der Larvalentwicklung als ventrale ektodermale Invagination des IX. Abdominalsegmentes mit einem einschichtigen Epithel angelegt. Durch intensive Zellteilung entsteht daraus während des 4. und 5. Larvenstadiums eine unregelmäßig zweischichtige Drüsenwandung. Mit beginnender Imaginalentwicklung degeneriert ein Teil der Zellen. Der eine Teil der übrigen entwickelt sich zu einem besonders gestalteten, am Lumen liegenden Gangepithel, der andere wird zum außenliegenden Drüsenepithel. 6. Bei allen untersuchten Arten gliedert sich die mediane Drüse in einen kurzen, von Muskulatur umgebenen, einschichtigen Ausführgang und den eigentlichen langen Drüsentubus. Arten, bei denen ein Eihüll-sekret auf dem Gelege nachgewiesen wurde, zeigen mit beginnender Eiablage eine Differenzierung des Drüsentubus in einen distalen (stärker sezernierenden) und einen kürzeren, basalen Abschnitt. Beide produzieren offenbar verschiedene Substanzen, wobei der im basalen Abschnitt gebildete Stoff wahrscheinlich im Dienste der Sekrethärtung steht. 7. Die Sekretion erfolgt apokrin und während der gesamten Imaginal-periode. Ein ausgeprägter Sekretionszyklus existiert nicht. Das histologische Bild der medianen Drüse ändert sich während der Imaginal-entwicklung. 8. Das auf den Eiern schaumige Eihüllsekret verläßt ungeschäumt den Drüsenporus und erhält durch die Tätigkeit der Gonapophysen des VIII. Abdominalsegmentes seine schaumige Konsistenz. Die zur Schäu mung dienenden Strukturen sind im Grundbauplan bei allen untersuchten Cercopiden vorhanden und wurden bei einigen offenbar erst sekundär in den Dienst der Schaumbildung gestellt. 9. Die Eihüllsekrete der Cercopiden dienen zum Festhalten der Eier an einem bestimmten Ort, zum Schutz vor Witterungseinflüssen, Feinden und Parasiten und möglicherweise als Luftreservoir und Schutz bei Überschwemmungen. 10. Erste Tastversuche zur Chemie des Eihüllsekretes vonPhilaenus spumarius wurden durchgeführt.

Notes: Abstract A comparative investigation of the chemical composition of Thalassiosira antarctica var. antarctica vegetative and resting stages revealed C:N and C:chl a ratios to be lower in vegetative cells. These trends primarily reflect vegetative levels of C/cell below, and N/cell and chl a/cell levels above those of spores. There was a change in chemical composition with the initial formation of resting spores, and spores continued to modify their composition while maintained in a cyclic light/dark regime for about one and one half weeks. Most notable was a net increase in carbon and chlorophyll a per cell. Spores then subjected to darkness for over one week appeared to retain most of the carbon and chlorophyll a previously synthesized. These findings support the idea that resting spores enhance the survival capabilities of a species under adverse conditions.

Notes: Abstract The adding of a mixed culture of marine hydrocarbon-degrading bacteria to petroleum polluted seawater did not increase the hydrocarbon degradation capability of the water. All the strains of the mixed culture disappeared from the dominant microflora while the autochthonous bacteria showed a capacity for adaptation to petroleum degradation about four days after the oil spill. This confirms the advantage of natural bacterial communities. The oil spilled on the sea surface evolved very quickly under the influence of abiotic factors such as sunlight. Aromatic petroleum fractions were oxidized and polymerized. This chemical evolution causes a drastic decrease of the biodegradability of crude oil.

Notes: Abstract The uptake and metabolism of 14C-L-leucine by Cystoclonium purpureum (Huds) Batt. (Rhodophyllidaceae) at concentrations of 0.5–50 μM were studied. Leucine was taken up from seawater at rates of 10–160 nmol·g-1 fresh weight·h-1. At low leucine levels ( 5 μM) the amino acid was preferably incorporated into cellular protein; amine formation was less than 5%. However at leucine concentrations of 50 μM, more than 30% of the total leucine taken up was decarboxylated to 3-methylbutylamine. This effect is expressed even more in Dumontia increassata (O. F. Müll) Lamour. (Dumontiaceae). In both species some of the amine occurred as a non-volatile derivative (bound amine) from which free amine could quantitatively be released by acid hydrolysis. Leucine and amine uptake were inhibited by CCCP. However, from cells preloaded with both leucine and amine, only free amine is released in the presence of CCCP. The results indicate that decarboxylase activity will be switched on at increased levels of amino acids in seawater which may be expected frequently in habitats of littoral algae (tidal zone). A possible function of amine formation and release within the scope of chemical defence of benthic algae is discussed.

Notes: Abstract An eight-hour exposure of Diploria strigosa (Dana) to a mixture of Arabian Light crude oil (19 ppm) and the chemical dispersant “Corexit 9527” (1 ppm) in a flowing seawater system reduced photosynthesis by symbiotic zooxanthellae by 85%, while either oil or dispersant alone had no effect. The greatest effect of crude oil plus dispersant occurred in the incorporation of photosynthetic products into lipids. Synthesis of was esters and triglycerides, the major storage lipids, was particularly affected. Total carbon fixation was restored within 3–5 h after treatment, and lipid synthesis was restored within 5–24 h after exposure.

Notes: Abstract The species and distribution of nematodes on the kelp Macrocystic integrifolia Bory, in the Bamfield region of Barkley Sound, British Columbia, Canada were examined. Nine species (belonging to six families) of nematodes were found on the kelp blades. Three species (Monhystera disjuncta, M. refringens and Prochromadorella neapolitana) comprised 91–99% of the nematode fauna and occurred in all monthly samples from July 1978 to November 1979. The three dominant species exhibited seasonal density differences. P. neapolitana occurred mostly in the summer, M. refringens abundance peaked from July to October and M. disjuncta was relatively abundant throughout the year. The other species contributed little to the overall abundance and distribution patterns. All three species occurred in greatest abundance on the lower and middle blades of M. integrifolia in the deep end of the kelp bed. Very few individuals occurred on the upper blades. Nematode distribution on M. integrifolia appeared to be related to blade age and the associated food sources on the blade.

Notes: Abstract The association of the alcyonarian Heteroxenia fuscescens (Ehrb.) with its cytosymbiotic algae shows structural and physiological adaptations optimizing the living together of the two partners as one functional unit. To enhance the energetic contribution of the autotrophic partner, the organization of the heterotrophic partner bears typical plant-like imprints. Up to 20% of the inorganic C photosynthetically fixed was translocated to the host (=2 mg C mg d.w.-1 d-1). This net C gain by the host is used for anabolic purposes including the deposition of storage material. Especially the wax-esters and triglycerides of the host-in contrast to those of the symbionts-were intensively labelled. The in-vivo 14C-fixation of zooxanthellae is more than double the in-vitro fixation. In both symbionts and host, the lipids show the highest relative 14C-incorporation. In particular the polyol component was strongly labelled. After 120 min of continuous incubation, approximately 40 labelled intracellular metabolites were detectable in the ethanol/water soluble fractions of zooxanthellae. Glycerol is the main low-molecular weight carbohydrate being transferred. This is corroborated by the deacylation of lipids of the host.

Notes: Abstract Female copepods of the species Centropages hamatus show decreased ingestion rates and decreased egg viability when exposed to crude oil/seawater dispersions having crude oil concentrations of 10–80 ppb. However, rates of egg production were not significantly affected by these exposure levels. In addition, we found no evidence for accumulation of petroleum hydrocarbons by copepods exposed to 200 ppb of South Louisiana crude oil. The results imply that biosynthetic pathways involved in oogenesis may be influenced by sublethal concentrations of crude oil or that petroleum hydrocarbons directly affect the viability of eggs. Recruitment into field populations of copepods could be severely reduced as a consequence of exposure to low levels of physically dispersed crude oil.

Notes: Abstract Female copepods of the species Centropages hamatus exposed to 80-ppb South Louisiana crude oil in seawater show alterations in their swimming activity, as expressed by the duration of pause intervals during swimming, mean swimming speed, and allocation of time to active food search. Behavioral patterns of oil-exposed copepods returned to patterns shown by control individuals after only 30 min of depuration in uncontaminated seawater. The results indicate that sublethal concentrations of hydrocarbons interfere with mechanisms of food perception in copepods, as in decapod Crustacea, either via blockage of receptors or via narcotization of the copepod's nervous system.

Notes: Abstract Amphipods, trapped at depths of 1 410 to 5 330 m and incubated in situ in the presence of a radiolabeled protein as a food source, were fractionated to measure the distribution of label in the major biochemical constituents: low molecular pools, ethanol and base soluble proteins, lipids, polysaccharides and nucleic acids. The results suggest lipid energy storage and enhanced microbial growth within the amphipod guts as compared to growth on the uningested food material. The merits and limitations of this general approach are critically evaluated.

Notes: Abstract This study was undertaken to investigate the natural variation of heavy metals in the polychaete Nereis diversicolor O. F. Müller and to examine this variation with respect to physiological and environmental parameters. During a 2 yr period from October 1980 to October 1982, concentrations of copper, zinc and iron in N. diversicolor from the Tees Estuary, North East England, were found to vary significantly with time. A seasonal influence on whole body copper concentration, in part related to the reproductive cycle, was observed. Zinc concentrations in N. diversicolor increased during periods of rapid growth and may represent a physiological demand for this metal. Whole body concentrations of iron appeared to be independent of size of worm, sexual maturation and sediment concentrations.

Notes: Abstract The effect of microalgal strength of adhesion to surfaces was examined with regard to their susceptibility to grazing by Gammarus oceanicus Segerstråle and Calliopius laeviusculus (Krøyer). Observations of the feeding behaviour and two feeding experiments were carried out under laboratory conditions. Naturally attached periphyton (strongly attached cells), homogenized periphyton (loosely attached cells), filtered phytoplankton (unattached cells) and bare surfaces (controls) were randomly located in a grid and offered for grazing to a fixed number of amphipods of each species separately. The number of individuals visiting each type of food presented in the grid was recorded for 24-h periods. The feeding habit of each species, their effect on food distribution and their efficiency at collecting small particles were also recorded. G. oceanicus has a low efficiency at collecting particles and does not select a particular type of food, owing to its feeding habit of indiscriminately resuspending loosely attached particles. C. laeviusculus is a highly efficient and selective grazer, preferring homogenized periphyton and phytoplankton to naturally attached periphyton. For epibenthic diatoms, strong adhesion to surfaces is advantageous to avoid grazers.

Notes: Abstract Various aspects of the biology of the blue manna crab Portunus pelagicus have been investigated in the large Peel-Harvey estuarine system of Western Australia, using samples collected regularly by beach seine, gill net and otter trawl between February 1980 and July 1981. Whereas crabs were widely dispersed throughout Peel Inlet, Harvey Estuary and the saline regions of tributary rivers during the summer and autumn, they were found mainly near the estuary mouth in the winter and spring. Since our data suggest that P. pelagicus has a preference for salinities of 30 to 40‰, the above changes in distribution are apparently related to the marked seasonal variation in salinity which results from the very seasonal pattern of rainfall. The number of ovigerous crabs in the estuary were greatest in January and February. The mean carapace width and number of eggs of ovigerous females were 110 mm (range 85 to 157 mm) and 509 433 (range 270 183 to 847 980), respectively. P. pelagicus started to reach the minimum legal size for capture (carapace width 127 mm) in the summer when they were approximately I yr old, and left the system in large numbers in the following winter when they were 15 to 20 mo old. These features explain why the fishery for P. pelagicus is highly seasonal, with the vast majority of crabs being taken between January and May. As crabs approached the end of their first year of life, the ratio of females began to exceed that of males, apparently as a result of the movement of males out of the system and legislation against the capture of ovigerous females.

Notes: Abstract The habitat, density and growth rate for an intertidal population of Concholepas concholepas (Bruguière, 1789) were studied at Las Cruces, Chile (Lat. 33°30′S; Long. 71°38′W) during 1977–1978. The growth rate (3.67 mm month-1) was determined in a newly settled group, whose average length was 11.3 mm, and whose age was estimated at 3 months. The densities found ranged between 1.1 and 107.3 “locos” m-2. Based on these results, the time of settlement of C. concholepas was calculated; capsule deposition, maximum maturity and recruitment reported by other authors for different localities are discussed.

Notes: Abstract The feeding pattern of kingklip (Genypterus capensis) off the coast of Namibia (Southwest Africa) was studied between 1980 and 1982. Fish (mainly Merluccius capensis) were the most abundant prey, and prey size increased with predator length. The results suggest that kingklip is a nocturnal benthic feeder and that larger prey items are caught by ambush or by stalking. The presence of only heads or the anterior portion of larger fish in kingklip stomachs and the relationship of this feeding habit with prey density would seem to indicate a certain degree of selective feeding and optimization strategy. Food consumption is 0.35–0.45% of the body weight per day. The incidence of predation on the hake population is also estimated, and consequently, almost one-fifth of the natural mortality of the 1–6 age groups of hake could be due to predation by kingklip.