ALBERT

Notes: Abstract Two types of possibly homologous glands different in structure and formation have been found. One of them is represented in C. vinula L. and N. anceps Goeze, it is an endocrine organ. The other in S. ligustri, S. ocellata, M. neustria and L. monacha has an excretory duct and therefore is an exocrine organ.

Notes: Abstract The occurrence of chitin has been demonstrated in heavily calcified Milleporidae (3 species) and Hexacorallia (4 species), but not in Octocorallia. Microfibrils, probably containing chitin, are arranged in a dispersed texture in these species and are embedded in a protein-containing matrix.

Notes: Abstract After the injection of Scribtol into the Arteria communis sinistra, the blood-supply to the spectacles, the iris, the vitreous humor, and the chorioid has been investigated with regard to the horizontal position of the pupil and to the binocularity.

Notes: Abstract A specimen of Ethmorhynchus anophthalmus Meixner 1938 contains a complex of supernumerary genital organs in front of the pharynx. The phenomenon elucidates some traits in the morphogenesis of the atrial organs.

Notes: Abstract The peritrophic membranes, which is several groups of animals are produced by midgut epithelia, have been investigated most thoroughly in insects. The following results concern Crustacea: In the peritrophic membranes chitin containing microfibrils are embedded in the ground substance consisting of proteins and mucopolysaccharides. In addition to a felt-like texture (“Streuungstextur”), microfibrils are arranged in textures of higher order (orthogonal texture — “Gittertexture”; hexagonal texture — “Wabentexture”).

Notes: Abstract The larvae of Cerura vinula L. and Notodonta anceps Goeze secrete formic acid for defence. The glandular protective system which forms the acid and changes of the cell structure were studied with the light-microscope.

Notes: Abstract The circulatory system of the leech Hirudo medicinalis was investigated by means of the latex method and in vivo experiments. For the first time the vascular configuration of the suckers and nephridia, and a unidirectional blood flow in all vessels are demonstrated.

Notes: Abstract The aedeagus of Psyllina, whose basic plan and function are described, exhibits several special differentiations of the ejaculatory duct. Some of them are suitable for taxonomic studies on the species level. These differentiations represent an autapomorphic complex of the Psyllina. Not a single feature proves any close relationship between Psyllina and single groups of Auchenorrhyncha.

Notes: Abstract. Morphogenesis of the canine teeth of the brown bear, Ursus arctos L., is described, based upon 101 skulls from the central Brooks Range, in arctic Alaska. The formation of annual layers in the calcified tissues (dentin and cementum) is attributed to interruption of growth and odontogenesis during the annual period of denning.

Notes: Summary Loblolly pine microtome sections 100μm thick were tested wet in tension. This thickness was approximately double the outside diameter of tracheids. Results indicate a curvilinear relationship between tensile strength and specific gravity of microspecimens combining both earlywood and latewood zones. Contrary to expectations the rate of change in slope of curve, expressed as tangent angles, decreased as specific gravity increased. Both tensile strength and stiffness values of these microspecimens are low in relation to their specific gravity. This reduction in strength and stiffness is probably related to the low ratio of microspecimen thickness to tracheid diameter, but needs further investigation. If the proper ratio between microspecimen thickness and tracheid diameter is determined, the transitional variation in tensile strength and stiffness within growth ring may be accurately established. The transitional variation in specific gravity can be successfully established from microtome sections, however the method is time consuming and not completely free of errors. This study is a part of a larger study that concerns the determination of several mechanical properties of the earlywood and latewood zones of southern yellow pine in relation to their anatomical characteristics. The part presented in this paper concerns the following objectives: 1. To determine whether microtome sectioned specimens can be successfully used to establish the transitional variation in physical properties within loblolly pine (Pinus taeda L.) growth rings. 2. To investigate the relationships between tensile properties and specific gravity obtained from testing microtome specimens within loblolly pine rings.

Notes: Summary Stress relaxation tests were performed with six tropical American species. Stress relaxation was not found to be a linear function of strain at any level of strain. At qual low levels of strain, stress relaxation in compression was much greater than in tension. A mechanical model consisting of an isolated spring in parallel with a spring and dashpot in series was used as an aid in the derivation of equations describing stress relaxation. An attempt to apply Newtonian viscous theory to the model was unsuccessful in accounting for rate of relaxation. However, when the hyperbolic sine law of viscous flow was applied, mathematically derived curves fitted the data very well. Stress relaxation appears to be related to “departure strain” which may be obtained readily from static stress strain diagrams.

Notes: Summary Light is one of the most important environmental factors influencing the cambium activity and consequently the formation of the secondary xylem. Its deficiency more or less inhibits the lignification of cell walls and also the formation of conductive tissues represented by the vessel system. From these results, if compared with those of bent stems, the conclusion may be drawn that some growth substances, namely the indoleacetic acid are the most important metabolites taking part in the formation of the quality of secondary xylem determined by the action of light. The importance of the total leaf area is assumed, acting as a perceptor of external light impulses and balancing to a certain extent the metabolic supply of the cambium by its own inertia.

Notes: Summary Two radial samples were sawn from nine levels in a single tree ofPinus kesiya Royle ex Gord. (syn.P. khasya, P. insularis). Twentyfive tracheids were measured on two microscope slides for the earlywood of rings 2... 21 in each radial sample. The statistically significant difference between radii had litile practical importance and the systematic difference between rings was consistent over all levels. The effect of differences between levels was important and multiple regressions were calculated, incorporating linear and quadratic effects of ring number and height in stem. The best model accounted for 82% of the total variation. Exponential regressions were calculated for each level independently (75... 89%) and for the entire tree (77%). Both types of model are acceptable for description of variation up to ring 21 but beyond this ring number the exponential model will be most useful for description and prediction. For future work the minimum sampling strategy per tree will be three levels, two radii per level, and three or four rings per radius if quadratic models are required; five or six rings will be necessary to fix exponential models.

Notes: Summary Since in these studies wood is used as basic material for the isolation of cellulose the structure and the composition of this planty substance were considered in greater detail. New measurements of the fiber dimensions and the thickness of the cell wall layers of typical springwood and summerwood tracheids in combination with data obtained from literature led to a model showing the most probable distribution of cellulose, polyoses, and lignin within the cell wall. The ultrastructural composition of the wood cell wall has been deduced from the properties and the behaviour of the cell wall components. The described model will be the basis for subsequent considerations.

Notes: Abstract Secondary xylem, or wood, is the tissue that conducts water and minerals in the tree; thus it performs physiologically one of the most important functions for the tree. In addition secondary xylem is the tissue that primarily determines the suitability of a tree for various economic uses. Investigation of the development of secondary xylem shows that it was gradual. Xylem mother cells, the immediate derivatives of cambial initals, were, at first, small cells with thin cell walls. Then the xylem mother cells enlarged radially, but still retained thin cell walls. When these cells reached the radial diameter of mature tracheids, the secondary wall deposition began. This continued until thick, rigid cell walls were attained. These thick, rigid walls determine the physical properties of a certain species of wood. This investigation shows that physical properties of tracheids can differ with stages of development.

Notes: Summary Embedding of small wood blocks for study of changes in pit structure during treatments of wood, such as various drying methods, may cause considerable damage to the pit membranes. The sapwood of three species was studied: Sitka spruce, Douglas-fir, and Pacific silver fir. Drying was done by air-drying, freeze-drying, and solvent-seasoning. The principal embedding medium used was butyl-methyl methacrylate. Other media used were celloidin, paraffin, and commercial epoxy and polyester resins. Damage to tracheid bordered pit membranes was found with all media and most woods and drying conditions, although there was much variation. In wood embedded in methacrylate monomers, the damage ranged from nearly aspirated pits, even in unseasoned wood which was solvent exchanged and diffusion embedded, to tori protruding from the aperture and to tori completely dislodged and removed from the pit cavity. The greatest pit damage occurred with nerver-dried wood, which was solvent exchanged and diffusion embedded. Air-dried spruce embedded in celloidin and commerically dried spruce embedded either in epoxy or methacrylate showed no appreciable displacement of tori. Freeze-drying of wood reduced but did not eliminate pit aspiration although the results are somewhat confounded with the effects of embedding. Embedded freeze-dried wood also showed pit damage. In solvent-exchanged embedded wood less aspiration occurred. Rupture of the pit membrane and torus displacement is probably caused by the stresses and plastic flow in the shrinking embedding medium during polymerization of resin systems or cooling of non-resin systems. Care must be taken in observing results of wood treatments that the observations are not brought about by the embedding method itself.

Notes: Summary The engineering design of furniture frames was investigated. The stiffness method of matrix structural analysis was applied to furniture frame design, and modifications of it which are needed to treat frames with semi-rigid, elastically non-linear joints of finite size were developed. A method of designing two-pin moment-resisting dowel joints was also developed. An experimental furniture frame was designed using the theories formulated. Results of tests performed on this frame agreed satisfactorily with those predicted theoretically.

Notes: Summary Pronounced tension wood from four North-American hardwood species has been examined by light and electron microscopy. Delignified fibers were also studied. The gelatinous layer was in all cases loosely attached to S2 but varied considerably in thickness within each species and was in one case terminated towards the lumen by a layer resembling S3. A terminal lamella was not observed. After considering both earlier evidence and the present results, it was concluded that the gelatinous layer has neither a honeycomb nor a homogeneous texture, as has been suggested, but that it consists of concentric lamellae of cellulose microfibrils. In the absence of hemicelluloses and lignin, the microfibrils are probably bound together less firmly than they are in other cell wall layers. The gelatinous layer is more readily separated from the remainder of the cell wall by mechanical forces than by chemical reagents.

Notes: Summary Pupl quality, in terms of a fiber shape factor S and a fiber length factor L, was determined for 96 pulps disk-refined from chips of varying characteristics. S was evaluated in terms of the Canadian Standard Freeness of the 48/100 fiber length fraction and is a parameter inversely proportional to specific surface. L is the percentage, by weight, of pulp retained on a 48-mesh screen and reflects the distribution by weight of fiber length in the whole pulp. S and L accounted for as much as 83 percent of the variation in handsheet properties. Properties were improved by using pulps displaying low values of S and relatively high values of L. Both S and L were related to specific refining energy and wood quality. S increased with increasing unextracted chip specific gravity and rings per inch of growth rate but decreased with increasing latewood content and refining energy. L decreased with increasing refining energy, rings per inch of growth rate, and unextracted chip specific gravity but increased with increasing latewood.

Notes: Summary The reasons for the interest in the rheology of wood and the favoured lines of research are stated. The response of wood can often be predicted adequately on the basis of previous studies but notable gaps remain in our knowledge. Future research should avoid going over well trodden ground and should concentrate on filling some of the gaps listed. The factor of greatest importance is the interaction of load with change in moisture content. International cooperation in rheological research on wood would be of great benefit.

Notes: Abstract The different types of the de Manian system are described and compared in 10 genera (for the first time in Viscosia and Oncholainmllus). By tracing a morphological sequence the organ is interpreted as a more or less segregated appendix of the female genital tube (duplication theory). The organ, which has distally an ingrowth of intestinal tissue, functions as a seminal receptacle.

Notes: Abstract The variations of the field, vein and edge scales of normal wings are compared with the variations of PS1-scales in nests in the same positions. Types and subtypes of these scales and their fluctuations are described. Length and width of field-scales are measured. The degree of polyploidy of blastocytes from scales is fixed. The susceptibility to change of the PS1-scales dependent on their position is not lost. The X-ray induced PS1 mutation is connected with the ultrastructure of the scale.

Notes: Abstract We successively examined the two main parts of the labium: the ligula and the palps. The organs located on the ligula have a simple innervation and may represent various types of mechanoreceptors. The palps are crowned by 13 different sensilla which have various receptions (mechanoreception, olfaction, gustation). Several described sensilla hold an unknown function.

Notes: Summary Research was carried out to reduce internal stresses in E. camaldulensis. Altogether, 74 trees of the Circeo National Park were examined; 25 eucalypts were girdled, the cut affecting the entire sapwood, while the remaining trees were taken as controls. They were utilized at different periods after girdling, viz. after 5, 8 and 17 months. The investigations were carried out on butt-logs (up to a height of 3 m) of which diametral boards, 3 m long, were taken, having a thickness proportional to the mean breast height diameter of each tree. The measurements were taken of a total length of 100 in. by a tensodeformometer with an approximation of 0.0001″, determining, together with the length, also the deflection of all the outer strips gradually removed from the board in order to evaluate the strip unit contraction. As concerns board lengthening, the arithmetical difference was determined between the lengths taken before and after the cut. While for unit contractions—expressed by 8 d/l 2 —the values are given in in./sq.in., for unit lengthenings the variations are given in inches. The results obtained must be considered as positive: in fact, deformations were reduced, on the average, to 50 percent. These positive results are accompanied by others, of practical nature, all supporting the effectiveness of the method followed. Mention should be made, in fact, that in sawing logs from control trees diverse cracks occurred very often along the pith, separating diametrical boards almost completely, while no fissure was observed on boards from girdled trees.

Notes: Summary The variation of the longitudinal Young's modulus with mean cellulose microfibril angle of the wood substance of the earlywood of a softwood has been determined from small clear samples. The longitudinal Young's modulus falls steeply as the angle between the longitudinal axis and the mean microfibril direction in the cell walls increases. The variation has been explained in both form and magnitude by applying the elastic theory of a fibre composite material with distributed fibre directions to a model of the experimental material. It confirms the two phase concepts of the plant cell wall, as far as the elastic properties are concerned, of rigid crystalline microfibrils embedded in an isotropic matrix of amorphous and paracrystalline materials.

Notes: Summary Several factors which may affect the shrinkage of wood had been studied using loblolly pine (Pinus taeda L.). It was observed that volumetric, tangential and radial shrinkages decreased as the height increased. Longitudinal shrinkage increased with height. Only tangential shrinkage was significantly affected by the distance from the pith factor. All shrinkages were found to vary significantly according to cardinal directions. For the trees studied, lower volumetric, tangential and radial shrinkages were observed for specimens from the south side of the pith. Longitudinal shrinkage was noticeably higher in this direction. Although shrinkage of wood for any given specific gravity was found to vary somewhat with trees, it was, in general, significantly affected by specific gravity. Volumetric, tangential and radial shrinkages increased with increasing specific gravity. The opposite was true for longitudinal shrinkage. According to regression equations derived from this study, tangential, radial and longitudinal shrinkage values were not zero but 2.79–3.45, and 0.526 percent, respectively, at zero specific gravity. Above 0.72 specific gravity, radial shrinkage of the species studied was found to be greater than tangential shrinkage. The effect of growth rate (number of rings per inch) on shrinkage was found to be insignificant.

Notes: Summary Infrared spectra (4000...250 cm-1) of thin sections (12μm) of woods from some pored gymnosperms of the order Gnetales and of a non-pored angiosperm of the family Winteraceae have been obtained and found to resemble closely the spectra of typical angiosperms rather than gymnosperms. These results indicate that the gross chemical composition of a wood is not related to its anatomical structure and show that chemically the Gnetales resemble angiosperms.

Notes: Abstract A method has been developed for the determination of lignin distribution in the wood cell wall by ultraviolet microscopy. The method incorporates some important advances on previus applications of UV microscopy to the study of lignin distribution. Ultrathin cross-sections of wood are obtained by the sample preparation and sectioning techniques of electron microscopy. The specimens are examined in monochromatic ultraviolet light using quartz reflection optics. The microscope image is photographically recorded and the negative is subsequently subjected to densitometric analysis. Each stage of the analytical procedure has been critically assessed to determine its validity and limitations. The method is ideally suited to the study of the removal of lignin from the wood cell wall during cooking and possesses other important applications in wood technology.

Notes: Abstract The distribution of lignin in black spruce has been determined quantitatively by the study of 0.5 μm transverse sections in a UV microscope. The average lignin concentration in the compound middle lamella was about twice that in the secondary wall. The lignin concentration of the middle lamella at the cell corners of adjacent tracheids was nearly four times that in the secondary wall but the volume of the secondary wall was much greater than the volume of the middle lamella. Thus, for earlywood, 72% of the total lignin was in the secondary wall leaving only 28% in the compound middle lamella and cell corner middle lamella regions. The corresponding values for latewood were 82% and 18% respectively. Use of oblique longitudinal sections of 0.1 μm thick permitted the resolution of the compound middle lamella. The lignin concentration in the true middle lamella was found to be equal to that in the cell corner middle lamella and the primary wall lignin content to be about twice that in the secondary wall.

Notes: Summary This paper describes fully the various patterns of bacterial attack to be observed in wood. It is based on many observations made with bacterially infected wood, both in pure laboratory cultures and in naturally attacked wood from diverse environments. Patterns of attack are described for tracheids, fibres, vessles and rays and three types of pit border decay are figured, together with attack of the pit margo and torus. A brief section also deals with the macroscopic appearances of wood subject to bacterial attack.

Notes: Summary InPinus taeda L., burst, breaking length, and sheet density were improved by using fiber refined from wood having long, narrow-diameter tracheids with thick walls. Only narrowdiameter tracheids with thick walls were required to improve tear factor. A theoretical stress analysis revealed that thick-walled cells of small outside diameter fail by diagonal tension or parallel shear, depending on the fibril angle, while under torsional stress during refining. Such failures result in ribbon-like fragments which research elsewhere has demonstrated to provide the coherence necessary for strength development in mechanical pulps. In contrast, thinwalled cells of small outside diameter fail by diagonal compression and yield few ribbons. Long fibers are more desirable than short fibers because of greater induced stresses and improved chances of axial alignment between the disks.

Notes: Summary The analysis of the torsion problem for a rod of orthotropic material is presented. The analysis is based on Norton's law generalised for a multi-axial state of stress for an orthotropic medium. The components of displacement have been assumed to be similar to those given by the theory of elasticity. The resultant stress τ at the periphery of the rod has been assumed to be a function of θ. An expression giving the twist as a function of the time has also been derived.

Notes: Summary The distribution of lignin in normal and tension wood of four hardwood species has been studied by examination in the electron microscope of the lignin skeletons remaining after removal of the polysaccharides with hydrofluoric acid. In normal wood fibers, the S1 had a higher lignin concentration than the S2 layer, which was not as highly lignified as in conifer tracheids. Vessels had a high concentration of lignin in both normal and tension wood, while the extent of lignification of the parenchyma was variable. In tension wood fibers, the S1 and S2 layers were highly lignified. A thick, unlignified G-layer was often associated with an extremely thin S2 layer with a high concentration of lignin. In both normal and tension wood, the lignin had the same orientation as the cellulose micro-fibrils in the different cell wall layers. The results confirm the earlier conclusion that, in the species investigated, the same amount of lignin is present in gelatinous as in normal fibers. Evidently, the lignification mechanism operates normally in the non-gelatinous layers of the fibers, as well as in the vessels and in the parenchyma of tension wood.

Notes: Summary Burst and tear strengths of handsheets made from 48 pulps disk-refined from chips of varying chemical composition decreased with increasing extractive content after the independent effects of fiber morphology were specified. This result was attributed to lessened bond strength caused by reduced surface tension forces and blocking of reactive sites on the fiber surfaces.

Notes: Summary The septate wood-fibres of Ribes sanguineum result from a genuine mitosis of the still functioning nucleus in lignified cells. The development of the septa occurs first in the vicinity of protoxylem and spreads centrifugally outwards and from the basis of the shoot towards the vegetative apex. Because there is no wall-layer fusion of the septum with the fibre-wall, the terms ‘chambers’ or ‘compartments’ are proposed for the partitions resulting from cytokinesis. The septum is built up by a middle lamella with primary-wall structures and plasmodesmata; it possesses a cellulose-pectin character and does not evince secondary wall appositions or lignification. During septum development a definite trend in the cytoplasmic organization of the living wood fibres is indicated. The probable significance of the various cytoplasmic organelles for the development and structure of the septa is discussed.

Notes: Summary The known requirements for the sorption and swelling of wood are reviewed. These are shown to be compatible, in the case of softwoods, with the following simplified model. The fibers are continuous with either rectangular or circular cross sections and lumen of the same shape with a constant size. The fiber walls consist of concentric lamina made up of small repeating units 100 Å by 100 Å, consisting of a microcrystalline core surrounded by an amorphous sheath. All sorption and swelling occurs at the surfaces of or within the amorphous sheath. The major portion of the sorption and swelling is inter-laminar with just sufficient intra-laminar sorption and swelling to avoid laminar distortion. Calculations give the generally accepted internal sorption surface for water of about 200 square meters per gram. The portion of the total sorption that is intra-laminar varies from 5 ... 20 percent in going from wood with a specific gravity of 0.3 ... 1.0. Thickness of sorption in water molecules per sorption site vary from 6.1 ... 4.9 for inter-laminar sorption and 0.35 ... 1.35 for intra-laminar sorption in going from wood with a specific gravity of 0.3 to one of 1.0. Similar values are obtained from experimental swelling data where lumen cross sections change. Similar calculations for super swelling of wood and pulps show that laminar separations may become sufficiently great to be microscopically visible. The calculations show that bound water fiber saturation points for wood normally fall in the range of 25 ... 40 percent. Super swollen wood, chemically isolated fibers and beaten fibers may as a result of reduced restraints have fiber saturation points greater than 150 percent. The latter are attributed to dispersion or diffusion forces rather than the conventional bound water forces of hydrogen bonding for intact wood.

Notes: Abstract A survey of comparative morphology of the pterothoracic pleurotergal musculature is presented, which is based upon dissections of representatives of 93 families of the Megaloptera, Planipennia, Hymenoptera, Protomecoptera, Eumecoptera, Diptera, Zeugloptera, Trichoptera und Glossata. This survey furnishes additional evidence for the evaluation of phylogenetic relationships between the orders of the Mecopteria.

Notes: Abstract The method for the search for synapomorphies (in the sense of Hennig) is demonstrated by the study of the system of sperm-transfer. The ground plan of sperm-transfer in Homoptera (and other insect groups) is peristaltic movement of circular muscles surrounding the ejaculatory duct. In contrast, Psyllina and Aleyrodina exhibit a completely different structure and function of the ejaculatory duct, being extremely specialized, and principally identical in both the groups. This is a synapomorphic complex which proves Psyllina and Aleyrodina as most closely related. Other synapomorphies confirm this statement.

Notes: Abstract The olfactory organs of all recent genera from the Actinistia (Latimeria) and Dipnoi (Neoceratodus, Lepidosiren, Protopterus) were studied morphologically, and compared with each other. Whereas the olfactory organ of Latimeria resembles that of the Brachiopterygii, the olfactory organ of the Dipnoi is similar to that, of the Elaemohra.nnhii and ArtinnnfarAraii

Notes: Abstract Adult Cenocorixa bifida (Heteroptera: Corixidae) emerging early in the year in British Columbia are all able to fly. Insects emerging in the late autumn look similar externally, but are incapable of flight: the ultrastructure of their indirect flight muscles resembles that of immature tissue, indicating a block in the normal myogenetic sequence.

Notes: Abstract The reef bass, Pseudogramma bermudensis, is an hermaphroditic percoid in which the testicular tissue is confined to a median lobe in the mid-dorsal wall of the oviduct. Development of an invagination of the ventral oviducal wall is correlated with the presence of maturing ova. These unique features indicate that Pseudogramma has had a separate evolutionary history and is not closely related to either the hermaphroditic Serranidae or the Grammistidae.

Notes: Abstract Structure and growth of a keeled tooth are discussed with Paracentrotus lividus as the main example. The microscopic structure of the tooth skeletons of other sea urchins was compared, considering at least one member of each family with the exception of Saleniidae. Attention is called to the necessary revision of the system of sea urchins.

Notes: Abstract Musculature innervated by the N. facialis inTheropithecus gelada (Rüppell) is patterned on broad lines in agreement with related genera of catarrhine monkeys, but presents some specializations and divergences in detail. Noteworthy is the extension to the labial margins superficially of the combined levator labii superioris and zygomaticus in the upper and the pars mandibularis of trachelo-platysma in the lower lip. A specialization of the medial fibres of levator labii superioris forms a sling-like structure within the upper lip and serves to implement the “lip-flip” gesture characteristic of the genus. Its antagonist is the orbicularis oris. Special features of all other facialis muscles are considered.

Notes: Abstract An electron microscopic examination of the KOSHEWNIKOW gland of the honeybee showed that the origin of the draining ductule extended into the gland cell through an invagination without actual cytoplasmic connection being made. The structure of the wall of the dendritic apical ramifications of the duct cell is very loose where it is in juxtaposition to the microvilli of the wall of the gland cell. In contrast, the rest of the duct wall is very dense.

Notes: Abstract Microfibrils in peritrophic membranes of insects — probably containing the chitin of these membranes — are arranged in only three types of texture. Sometimes these types of texture are convergent. Different stages of a given species have the same type of texture. Although in some orders the same type of texture occurs in all those species which have been investigated, there is no conformity in others. There seems to be no correlation between type of texture and either mode of formation of peritrophic membranes or nutrition of the insect.

Notes: Abstract The surface structure of the fracture in the exuvia of Limulus caused by the shedding of the exoskeleton is compared with the fine-structure of experimentally induced fractures using the electron microscope, Stereoscan.

Notes: Abstract The third part of the study on the symbiosis of the Palaeococcoidea deals with the Drosichini, Monophlebulini, Llaveiini and Iceryini. Comparative considerations on the total field conclude the research of several years.

Notes: Abstract The King penguin epidermis has a stratum corneum of flattened solidly keratinized cells without basophilic nuclear remnants. It contains keratin bound substances and is without an underlying stratum granulosum. The insunken feather follicles and the thick phospholipid-rich cornified layer appear to be adaptations for aquatic life.

Notes: Abstract Lateral appendages on the mesothorax of flea pupae, regarded to be “wing buds” by Sharif, have been found in species of the Ceratophylloidea investigated by other authors and me, but not in the Pulicidae. The appendages become basal parts of the mesepimeron which speaks against their wing character. Ecological data are given.

Notes: Abstract In Nannacara anomala rods and single and double cones as well as the horizontal cells are arranged in a regular pattern. During dark adaptation only the single cones move distally and leave their places to the rods. Each unit consisting of 4 double cones, 1 single cone and 4 rods has its own horizontal cell; each double cone however, belongs to two of these units at the same time.

Notes: Abstract On the coast of Sylt (North Sea) two new families of calyptorhynchid Turbellaria were discovered. TheAculeorhynchidae belong to theEukalyptorhynchia because they have a proboscidial cone. The isolating structures are two glandular tubes armed with cuticular hooks. TheNematorhynchidae are placed in theSchizorhynchia because their proboscis has a dorsal and a ventral lip. The specific marks are cuticular hooks on these lips and a muscular tube involving the proboscis gland sacs.

Notes: Abstract The scent-production and the scent-delivery in the posterior larval gland of the cotton bug Dysdercus intermedius Dist. was explored by means of light microscopy and electron microscopy.

Notes: Abstract Filtration rates and the extent of phagocytosed food particles were determined in the offshore lamellibranchs Artica islandica and Modiolus modiolus in relation to particle concentration, body size and temperature. Pure cultures of the algae Chlamydomonas sp. and Dunaliella sp. were used as food. A new method for determining filtration rates was developed by modifying the classical indirect method. The concentration of the experimental medium (100%) was kept constant to ±1%. Whenever the bivalves removed algae from the medium, additional algae were added and the filtration rate of the bivalves expressed in terms of percentage amount of algae added per unit time. The concentration of the experimental medium was measured continuously by a flow colorimeter. By keeping the concentration constant, filtration rates could be determined even in relation to different definite concentrations and over long periods of time. The amount of phagocytosed food was measured by employing the biuret-method (algae cells ingested minus algae cells in faeces). Filtration rates vary continuously. As a rule, however, during a period of 24 h, two phases of high food consumption alternate with two phases of low food consumption during which the mussels' activities are almost exclusively occupied by food digestion. Filtration rate and amount of phagocytosed algae increase with increasing body size. Specimens of A. islandica with a body length of 33 to 83 mm filter between 0.7 to 71/h (30–280 mg dry weight of algae/24 h) and phagocytose 21 to 122 mg dry weight of algae during a period of 24 h. The extent of food utilization declines from 75 to 43% with increasing body size. In M. modiolus of 40 to 88 mm body length, the corresponding values of filtration rate and amount of phagocytosed algae range between 0.5 and 2.5 l/h (20–100 mg dry weight of algae) and 17 to 90 mg dry weight of algae, respectively; the percentage of food utilization does not vary much and lies near 87%. Filtration rate and amount of phagocytosed algae follow the allometric equation y=a·x b. In this equation, y represents the filtration rate (or the amount of phagocytosed algae), a the specific capacity of a mussel of 1 g soft parts (wet weight), x the wet weight of the bivalves' soft parts, and b the specific form of relationship between body size and filtration rate (or the amount of phagocytosed algae). The values obtained for b lie within a range which indicates that the filtration rate (or the amount of phagocytosed algae) is sometimes more or less proportional to body surface area, sometimes to body weight. Temperature coefficients for the filtration rate are in Arctica islandica Q10 (4°–14°C)=2.05 and Q10 (10°–20°C)=1.23, in Modiolus modiolus Q10 (4°–14°C)=2.33 and Q10 (10°–20°C)=1.63. In A. islandica, temperature coefficients for the amount of phagocytosed algae amount to Q10 (4°–14°C)=2.15 and Q10 (10°–20°C)=1.55, in M. modiolus to Q10 (4°–14°C)=2.54 and Q10 (10°–20°C)=1.92. Upon a temperature decrease from 12° to 4°C, filtration rate and amount of phagocytosed algae are reduced to 50%. At the increasing concentrations of 10×106, 20×106 and 40×106 cells of Chlamydomonas/l offered, filtration rates of both mollusc species decrease at the ratios 3:2:1. At 12°C, pseudofaeces production occurs in both species in a suspension of 40×106, at 20°C in 60×106 cells of Chlamydomonas/l. At 12°C and 10–20×106 cells of Chlamydomonas/l, the maximum amount of algae is phagocytosed. At 40×106 cells/l, the amount of phagocytosed cells is reduced by 26% as a consequence of low filtration rates and intensive production of pseudofaeces. At 20°C and 20–50×106 cells of Chlamydomonas/l, the maximum amount of algae is sieved out and phagocytosed; the concentration of 10×106 cells/l is too low and cannot be compensated for by increased activity of the molluscs. With increasing temperatures, the amount of suspended matter, allowing higher rates of filtration and food utilization, shifts toward higher particle concentrations; but at each temperature a threshold exists, above which increase in particle density is not followed by increase in the amount of particles ingested. Based on theoretical considerations and facts known from literature, 7 different levels of food concentration are distinguishable. Experiments with Chlamydomonas sp. and Dunaliella sp. used as food, reveal the combined influence of particle concentration and particle size on filtration rate. Supplementary experiments with Mytilus edulis resulted in filtration rates similar to those obtained for M. modiolus, whereas, experiments with Cardium edule, Mya arenaria, Mya truncata and Venerupis pullastra revealed low filtration rates. These species, inhabiting waters with high seston contents, seem to be adapted to higher food concentrations, and unable to compensate for low concentrations by higher filtration activities. Adaptation to higher food concentrations makes it possible to ingest large amounts of particles even at low filtration rates. Suspension feeding bivalves are subdivided into four groups on the basis of their different food filtration behaviour.

Notes: Abstract Micro-zooplankton populations in the upper 100 m were sampled from 5 marine environments in the northeast Pacific Ocean extending from slope waters off San Diego to an oceanic site near Isla Guadalupe, and their abundance related to that of the larger zooplankton, phytoplankton (as estimated from chlorophyll a), and detritus. The micro-zooplankton and other components of the seston were subdivided into 3 fractions on the basis of size in the deck-mounted collecting unit of a seawater pumping system. Through the euphotic zone at each site, the Protozoa, of which ciliates were the dominant forms, accounted for 95% or more of the total micro-zooplankton numbers. Their biomass, as volume, was estimated to be 13 to 28% of that of the total micro-zooplankton. The standing stock of micro-zooplankton over the euphotic zone at the various sites, in terms of dry weight, was estimated to be 14 to 34% (average 23%) of that of the phytoplankton crop. Micro-zooplankton volumes in the upper 100 m were 21 to 26% of those for the larger zooplankton sampled over the same depth.

Notes: Abstract We have studied carbohydrate metabolism in the marine environment by means of the isolation and characterization of carbohydrates of particulate matter from various depths. The present work is especially concerned with water-extractable carbohydrates of the particulate samples from 11 stations of the northwest Pacific Ocean. Water-extractable carbohydrate content in the particulate matter of the surface waters was measured; it ranged from 19.2 to 36.0% of the total particulate carbohydrate. These values decreased, ranging from 6.5 to 15.5% at 50 m depth. Such rapid vertical change of the concentration of the carbohydrate indicated that it was lost from the particulate matter much faster than the other particulate organic constituents such as protein and water-insoluble carbohydrate. This process left water-insoluble carbohydrate in the deep-water particulate matter as previously observed in the Sagami Nada, off eastern Honshu, Japan. Upon acid hydrolysis, water-extractable carbohydrate revealed glucose ranging from 67.0 to 84.2%. Rhamnose, fucose, ribose, arabinose, xylose, mannose and galactose were also identified as components of the carbohydrate fraction. Carbohydrate studies on the laboratory cultured diatoms clearly indicated that the water-extractable carbohydrates were food reserve materials of the diatoms. In view of this fact, the metabolism of the water-extractable carbohydrate in the euphotic zone and its underlying layer is discussed.

Notes: Abstract The calanoid copepods, Acartia clausi Giesbrecht and Acartia tonsa Dana, are maintained at high densities in continuous culture at 15°C. Synthetic sea-water medium is recirculated through filters and a foam tower which limits accumulation of dissolved wastes and various metabolites. The ciliate Euplotes vannus Müller is associated in culture with the copepods, and effectively controls bacterial population and accumulation of algal debris. The copepods graze upon the ciliates as well as upon the phytoflagellates Isochrysis galbana Parke and Rhodomonas baltica Korsten.

Notes: Abstract More than 6000 individuals of the snailLittorina littorea L., from 6 different localities on the coast of the German Bay (North Sea), were examined for larval trematodes by crushing their shells, an additional 6000 by isolation in small quantities of sea water. Six species of larval trematodes were found inL. littorea and described: Notocotylid larva —Cercaria lebouri Stunkard, 1932; Cercaria ofHimasthla elongata (Mehlis, 1831); Cercaria ofPodocotyle atomon (Rudolphi, 1802); Cercaria ofRenicola roscovita (Stunkard, 1932) n. comb.; Metacercaria ofMicrophallus pygmaeus (Levinsen, 1881); Cercaria ofCryptocotyle lingua (Creplin, 1825). Considering the large number of investigated snails, the trematode fauna ofL. littorea in this area is assumed to be completely known. The life cycles ofHimasthla elongata andRenicola roscovita are described. Larvae of the different trematode species show differential preferences for distinct size groups of snail hosts. Juvenile snails are not infected. No correlation exists between infection rates and sex of the hosts. Quantitative aspects of multiple infections are calculated and discussed. The incidence of larval trematodes in the investigated localities differs. Information is presented on seasonal variations of infestations and their possible causes.

Notes: Abstract The myosin ATPase activity of the flexor muscle of an estuarine crab, Scylla serrata, was studied in relation to salinity adaptation. The enzyme is activated more by calcium than by magnesium; it exhibits maximum activity at pH 9.0, and substrate inhibition above 0.5 mM ATP. The enzyme activity increases in crabs adapted to higher salinities. The enzyme from normal (70% sea water) crabs shows two pH optima; one at pH 7.0, the other at pH 9.0. The neutral optimum shifts to pH 6.0 upon adaptation to full strength sea water, but disappears upon adaptation to 25% sea water. The enzyme from normal crabs shows an optimum at 30 °C; adaptation to full strength sea water raises this optimum to 38 °C, whereas adaptation to 25% sea water decreases it to 24 °C. These changes are discussed in relation to estuarine conditions.

Notes: Abstract In a series of studies to develop an effective high speed plankton sampler, hydrodynamic research was carried out on a modified model of the Clarke Jet Net. A theoretical analysis of the motion of the sampler was made using an IBM 7040 computer, and test tows were made in an experimental ship tank and at sea. To maintain the roll angle of the sampler at approximately zero, a v-shape bridle was applied. A pair of towing holes should be selected for the particular range of towing velocity. The calculated longitudinal stability seemed good in all the cases examined. Towing tests in the ship tank at 2 to 3 m/sec revealed sufficient stability. The motion of the sampler at speeds higher than 3 m/sec can be assumed from hydrodynamic coefficients derived from the ship tank experiment. Towing-cable characteristics, assumed by computation, indicated that about 500 m at 6 kt and 1,000 m at 12 kt should be paid out to lower the sampler down to 100 m. The effect of the sampler on the cable is found only adjacent to it and is almost negligible beyond 50 m from it in depth. Results of sea tests at 6 and 9 kt confirmed the stability of the sampler. Examination of the catch suggested that the present model can be used, with some modifications, for the quantitative and qualitative sampling of large zooplankton.

Notes: Abstract A condenser has been designed to fulfil the need for high quality dark-field illumination of transparent zooplankton animals. The condenser, which covers fields of up to 30 mm, is designed for use on a stereomicroscope. The condenser uses only reflectors so that it can be constructed without the use of optical glass. A system for permanently fixing the microscope, condenser, light source, cooling system and optional rotating tray is presented. Coupled with an electronic flash, the condenser is an important tool in investigating structural and functional features of living animals. Examples of its use in describing some aspects of the biology of living specimens of the salp Thalia democratica are given.

Notes: Abstract This paper presents facts and problems related to the concept of critical salinity, i.e., the salinity range 5 to 8‰ S. It points, in particular, to the distribution of marine and freshwater species revealing a faunistic boundary (minimum number of species), organismic resistance to salinity, osmoregulative capacity, physiological activity, electro-chemical properties of tissues, and evolutionary aspects. The concept of critical salinity opens up new perspectives for the understanding of present day salinity effects as well as for the interpretation of animal evolution.

Notes: Abstract Zooplankton samples collected in the Gulf of Marseille with a system of 10 horizontal nets permitted the study of the stratification in the upper first meter. The pontellid copepod Anomalocera patersoni Templeton is a very typical species in this near-surface biotope. Its occurrence in the uppermost water layer (0 to 10 cm) is denser than in the others. This copepod shows the greatest decrease of population density between the first and the second layer, and becomes rare from 40 to 100 cm.

Notes: Abstract The study of the cycle of chaetognaths during 1967 was carried out using samples collected with a Juday-Bogorov net at 1 station in the entrance of the bay by vertical hauls (75 m-0 m). Among the 13 sorted categories of chaetognaths, the principal component analysis singles out 2 communities (made up from the abundant species) and 3 isolated species. The first 3 components carry 71.1% of the total variance. An attempt to identify components, using partial correlations, shows that the first component is a trophic relation, the second the vertical stability of the water, the third a factor of development of young stages. The correlation between the physical and biological factors and the components account for 45% of the total information.

Notes: Abstract The chemical composition of the white and red lateral muscles of the clupeid fish Harengula humeralis (Cuvier) was investigated; water, protein, nonproteic nitrogen, lipid and glycogen content were determined. Comparison was made with the liver in regard to lipids and glycogen. Fractionated protein extractions were performed, with a view to separate sarcoplasmic, myofibrillar and stroma proteins. The following results were obtained: the red muscle contains less water, more glycogen and more lipids than the white muscle; the lipid content of the former is approximately the same as that of the liver and the glycogen content is greater per unit of tissue mass; the total glycogen content of the red muscle tissue is about 12 times greater than that of the liver (based on literature data, a correlation is established in this respect with the ecology of different fish species); the red muscle contains significantly more sarcoplasmic proteins than the white one. The conclusion is drawn that the lateral red muscle is the main storage tissue for energy reserves of the musculature in pelagic fishes, and that its main role in the organism is a metabolic one. Attempts were made to record action potentials from the 2 muscles, but the true origin of those recorded from the red muscle was not clear.

Notes: Abstract Collections of Branchiostoma lanceolatum (Pallas) made in mid-May and mid-July at Helgoland before and after spawning have established that the larvae leave the amphioxus ground about June and therefore presumably become planktonic. Metamorphosing larvae and young adults can be collected on the ground in late August and early September and are either the same larvae returning, or others from a neighbouring ground within the same circulating current system. An examination of the gut contents of 67 larvae collected from the plankton at Helgoland in August showed that 30% of the animals had ingested calanoid copepods or other organic material of a size similar to that of the larval mouth. A few larvae had also taken small particles evidently by a ciliary mechanism. In 50% of the larvae the gut was empty. It has been found that, in addition to a muscular mouth and gill bars richly supplied with nerves, both the gut wall and the body wall are muscular and capable of passing, by peristalsis, large food masses that distend the body. The visceral muscles of the larva resemble the coelomyarian fibres of the Nematoda. The larva appears, therefore, to be both microphagous and macrophagous. Evidence from the swimming behaviour and from reports of the vertical distribution of larvae in the sea is discussed. It is suggested that the larvae normally swim upward with the mouth and gills closed and then sink passively in the horizontal position with the pharynx expanded and the open mouth directed downward. In the event of large organism such as a copepod or a mass of organic material coming into contact with the adhesive lower left surface of the larva, it could be captured by the mobile lower lip and engulfed. The straightening of the larval tail, the great increase in the number of eyecups and the growth of the metapleura at metamorphosis are suggested as factors leading to the settlement of the young adult. Attention is drawn to the possible significance of the structure of the larva in interpreting the relationships of the cephalochordates.

Notes: Abstract This paper is the result of an investigation into the regulation of oxygen intake in silver eels, Anguilla vulgaris L. Measurements of oxygen intake in intact and operated animals were taken both for gills and body skin. The temperatures of head and body could be varied independently from each other, so that the eels could be exposed to identical or differing head and body temperatures; the spinal cord of operated eels was either cut through just below the head or destroyed in the body region. In comparison with intact eels, oxygen intake of operated individuals shown no significant change due to the destruction of the central nervous system. In general, oxygen intake of the gills shifts noticeably after temperature changes of as little as 4°C, administered at the head region or the body; this shift appears first in the body skin after an 8°C-change in the body. Changes in head temperature produce no significant change in oxygen intake of the body skin. According to temperature measurements conducted by thermo-couples, a temperature change in the body is not transferred to the brain. It is assumed that eels are able to “measure” the oxygen tension of their venous blood on its way from the heart to the gills, and to use this information for regulating their oxygen intake.

Notes: Abstract Analysis of 25 midwater trawl collections, disposed along the meridian 70°20′W from off Hispaniola to the Gulf Stream, showed a change in the mesopelagic fish fauna at about 27°N. The point of faunal change corresponded to a change in the temperature structure of the upper part of the water column, i.e., at a (the?) so-called “thermal front”, perhaps identical to the so-called “North Atlantic subtropical convergence”. Of 44 species occurring in four or more collections, 13 species were collected only to the north of the front and 1 species only to the south. By most criteria, north-of-the-front collections were larger than southern ones. This is in accord with the north-south difference in primary production noted by other workers which, in turn, seems atributable to the north-south difference in temperature structure. To the north the upper part of the water column is well stratified in summer only, while to the south it is well stratified at all seasons. Taken altogether, what is now known suggests that the thermal front logically divides the upper Sargasso Sea into northern and southern portions that differ in many ways.

Notes: Abstract The increases in constituents per unit weight of eggs during embryonic development of the gastropod Crepidula fornicata amounted to 14.6% for ash, 1.0% for protein, and 0.3% for non-protein nitrogen. During the same stages, fat content decreased from 33.7 to 20.3%, carbohydrate from 10.2 to 7.7% and energy content from 6209 to 5298 cal/g dry organic substance. The cumulative efficiencies for yolk utilization were 83.8% for dry weight, 61.0% for energy, 85.1% for protein, 50.7% for fat, and 63.6% for carbohydrate. A single egg contained 0.0269 cal, a single veliger 0.0164 cal. Of the 0.0105 cal expended on metabolic processes of the embryo, oxidation of fat contributed as much as 65.3%, while that of protein and carbohydrate amounted only to 18.8 and 6.3%, respectively. On the basis of ecophysiological considerations, a new classification of eggs is proposed.

Notes: Abstract Two new forms of the copepod genus Tisbe, one of which was found in the Lagoon of Venice near Chioggia (Italy), and the other in the port of Malta, have been studied. Although showing a striking resemblance in morphology, all attempts to cross representatives of the 2 populations have failed. They may, therefore, be considered as “sibling species”. Even on closer study, no qualitative structural differences between them were found. However, careful analysis of some biometrical traits revealed significant differences. A certain differentiation of another kind emerges from the comparison of the life-cycle and population dynamics. Under standard laboratory conditions the following main parameters have been considered: (1) survival; (2) mean and minimum generation time, T; (3) net reproduction rate, R 0; (4) intrinsic rate of natural increase, r m. The significance of the findings is discussed.

Notes: Abstract Primary productivity studies were conducted at the White Sea Biological Station, Payakonda, during summer 1966. Oxygen and radio-carbon methods were employed; the oxygen method gave higher results. Variations in productivity due to tides were measured; low tide waters supported higher productivity rates.

Notes: Abstract Phytoplankton cycles of lower Saronicos Bay, Aegean Sea, are described on the basis of net samples collected during 1967. The annual cycle is largely due to changes in diatom concentrations (cells/liter). The diatom summer poverty is due mainly to high light intensities, phosphate depletion and extensive grazing. The species succession and diversity have been examined, and the results are discussed.

Notes: Abstract This paper investigates the dependence of phytoplankton production upon rhythm and rate of zooplankton grazing and presents a mathematical model for calculating the most important parameters. Both uniform and non-uniform grazing are described mathematically. Non-uniform grazing, expressed by a sinusoidal curve, is usually found in bathyplanktonic ecosystems with migratory consumers. Phytoplankton production depends on the time of grazing; the nearer grazing occurs toward nightfall, the higher is the phytoplankton production. In order to calculate phytoplankton productivity and the amount of food consumed by the zooplankton, experimental data on generation time of phytoplankters, their mortality rates, initial and final standing stocks, and information on diurnal grazing rhythms must be available. If the distribution of grazing rates is sinusoidal and mortality rate constant, the equations presented allow the calculation of phytoplankton productivity with an error of about 6%.

Notes: Abstract Newly hatched Convoluta convoluta (Abildgaard) are always without symbionts. They acquire the organisms, which later become their zooxanthellae, with their food. In the field this is an automatic process, since C. convoluta without zooxanthellae have never been reported. The main diet of the young C. convoluta are various diatoms and spores of red algae. The symbionts of C. convoluta originate from diatoms of the genus Licmophora. This fact has been established in young specimens both in the sea and in laboratory cultures. Freshly hatched C. convoluta were fed with Licmophora hyalina (Kütz.) Grunow and Licmophora communis (Heib.) Grunow. Licmophora cells, capable of infesting C. convoluta, slip out of their silica shells and later occur between the cells of the peripherical parenchyma. High population densities of zooxanthellae, produced by numerous divisions of the naked diatom cells, are only possible in the host's parenchyma if the young C. convoluta continue to feed. Adult turbellarians with a high population density of symbionts feed less than the young, but never stop food uptake completely. Artificial infestation with symbionts can be brought about by making sub-adult turbellarians take up isolated zooxanthellae as food. Symbionts outside their host neither propagate nor regenerate silica shells in the culture medium employed. The obligatory nature of the mutual interrelation between C. convoluta and zooxanthellae has been proved by the great difficulties in rearing symbiontless individuals, and by starvation experiments both with sub-adults containing only a few symbionts and adults coloured brownish due to a compact layer of zooxanthellae.

Notes: Abstract Quantitative determination of living organic matter (micro-organisms) in the ocean were made using the adenosine triphosphate (ATP) assay. Strehler and Totter's (1952) method was used. A simple apparatus recorded the photons emitted from the very beginning of the photochemical reaction; the assay is specific for ATP but enzymes present in Photynus pyralis suspension may create errors. The sea-water ATP values in Marseilles Bay range between 2.10-2 and 80.10-2 mg per m3. An offshore profile of the Mediterranean Sea, near Toulon, gives values around 10-3 mg/m3. Protein assays have been made on the same samples. The differences existing between certain values in the series are attributed to inert particles.

Notes: Abstract A study of hydrographical and biological parameters has been undertaken in surface waters near the mouth of the Rhône. Salinity, temperature and nutrient salts have been recorded, and the phytoplankton, as well as the zooplankton, quantitatively and qualitatively analyzed. Furthermore, the concentrations of chlorophyll a, seston, and organic matter have been determined. The hydrographical structure near the Rhône is heterogenous. The biological results are diffcult to explain on the basis of hydrographical parameters. The numerical data of zooplankton in the investigated area are 10 times higher than those of the Mediterranean Sea. There is a great abundance of brackish and freshwater phytoplankton in the dilution zone, but these cells are dead or almost dead; these observations coincide with the low concentrations of chlorophyll a.

Notes: Abstract Herring larvae were obtained via artificial spawning (Baltic spring spawners, Downs herring). Eggs were immediately transported to the Marine Station (“Meeresstation”) of the Biologische Anstalt Helgoland, transferred into 140] tanks, and incubated at about 10°C. Sea water was circulated through an internal filter. Artificial illumination (neon tubes) was kept at about 1000 Lux (water surface) during 12 h per day; it was than decreased gradually to complete darkness within 30 min. Dawn was also simulated in order to avoid abrupt changes in light intensity. Food consisted of wild plankton (mainly crustacean nauplii) caught every day on Helgoland Roads, and of Artemia salina nauplii. The larvae were fed 1 to 3 times a day; they took the food always within the first half hour after it was offered. Over periods of 5 min each, the time spent for various activities (different modes of swimming, feeding) were recorded. The behavioural patterns of comparable larvae were filmed. The initial phase of prey catching consists of s-shaped body bending; usually the main bend of the body (upper arrows in Figs. 2 and 3) bears a typical directional relationship to the swimming path of the prey focussed (lower arrows). Such body bending is not always succeeded by subsequent steps of prey catching. In the normal prey catching process, aiming is followed by sudden stretching of the body and swallowing of the prey within 0.2 to 0.3 sec. Yolk sac larvae can use their pectoral fins, larvae of more then 15 mm total length also their tail- and dorsal-fins, for stabilization and correction of prey catching movements. In yolk sac larvae, complete prey catching lasts about 1 to 3 sec. Percentage successful prey catching manoeuvres increases with age and experience (Table 2). Initial success percentage was about 1% in Baltic Sea larvae (Kiel) and about 10% in Downs larvae; it rose within 30 to 35 days in Kiel larvae to nearly 60%, in Downs larvae to over 70%. The possible reasons for these differences are discussed; they may be related to body size and composition of planktonic food. Visual perception of food depends on optic capacities of larvae, size and distance of prey, visibility, and “duration of presentation” (time span during which the image of the prey is projected onto the retina). This, in turn, appears to be subject to frequency and amplitude of undulating movements of the head during swimming. The percentage of body positioning for prey catching attains maximum values at prey distances of 2 to 8 mm in yolk sac larvae (Downs), and of 3 to 40 mm in larvae of 15 to 20 mm body length; it decreases steadily with increasing prey distance. Larvae up to 15 mm total length take mainly copepod nauplii, larger larvae preferably copepodites. Distance of prey perception is wider in the horizontal than in the vertical plane; in fact, larvae do not perceive prey underneath the horizontal plane.

Notes: Abstract Seven years of investigations on the so-called “Grand Récif” at Tuléar (south-western coast of Madagascar) lead the authors to put forward several hypotheses about the trophic structure of this biocoenotic complex. The Tuléar coral reef seems to be an almost autarchic system, with a very important benthic primary production by xanthelles, epiphytic diatoms and blue-green algae, and perhaps “green filaments” (Ostreobium); the energetic contribution from planktonic production seems to be rather small. A very important content of organic aggregates in the reef waters probably results from the high production of mucus by most of the corals and similar organisms (mainly zoantharians). This “paraprimary” production is trapped in the coarse sand banks and in the “mesh” of the reef (see below). The fauna of small invertebrates, belonging mainly to the secondary link of the food chain, is very rich in the small holes and crevices existing in the reef mass, but scarce in the biocoenoses on the reef surface. The dead parts of the reef have a “mesh” structure which confines most of this fauna representing the secondary level of the food pyramid. The production of fish in the reef coral environment is poor, probably because of the blocking of most of this secondary production in the reef's “mesh” structure; in this alveolary system a gigantic wasting of animal production takes place, which makes the trophic structure of the coral reef complex and quite unbalanced.

Notes: Abstract Along the Northumberland coast, Zirphaea crispata (Linné) occurs in soft shales from approximately 1 ft (0.2 m) above datum to at least 20 fathoms (37 m). It also occurs sublittorally in dumped power station fly ash wastes. The populations are polymodal. Growth rate is estimated at approximately 8 mm a year with a life span of approximately 5 years in the case of those found intertidally and 6 to 7 years in the case of the sublittoral populations. Although breeding occurs from March to October, there is evidence that there are two main breeding peaks, one from March to May and the other from August to October. Differences in shell shape between different populations can probably be explained by the differences in effort required to drill into the substratum.

Notes: Abstract Asterina gibbosa from Marseille, a protandric hermaphrodite is considered belonging to a balanced sexual race similar to the Dinard (France), Plymouth (England) and Banyuls (France) reces. Spermatogenetic activity is seasonal. Sexreversal occurs when animals are 3 years old (average arm length (R)=12 mm). Ultimately, sea-stars with ovogenetic reactions could produce a spermatogenetic resurgence. Few individuals are “permanent males”.

Notes: Abstract An investigation of the free amino acid patterns of 67 species representing 50 genera of West Indian Demospongiae has been undertaken to examine the value of this biochemical approach in adding another parameter to phylogenetic inquiries. Two-dimensional thin-layer electrophoresis and chromatography were used to separate mixtures of naturally occurring ninhydrin-positive compounds. Individual components were identified as far as possible, and the fingerprints or patterns of the species studied were used as a basis for evaluating relationships. The subclass Ceractinomorpha is a relatively homogeneous group, with free amino acid patterns characterized by a consistent representation of protein amino acids and by the absence of compounds other than taurine and hypotaurine in the neutral region of the chromatogram. Two variants of this general pattern can be recognized, one found in the orders Dictyoceratida and Poecilosclerida, the other occurring in the order Haplosclerida and the family Halichondriidae of the order Halichondrida. Unexpected results within this subclass are the wide separation of the dictyoceratid families Spongiidae and Verongiidae, the anomolous patterns of the genera Agelas and Iotrochota and of the family Callyspongiidae, and the suggestive affinities of the family Hymeniacidonidae with the order Hadromerida. The subclass Tetractinomorpha appears to represent a polyphyletic assemblage in which 5 recognizable patterns can be distinguished. These represent the orders Homosclerophorida, Choristida, Spirophorida, Hadromerida and Axinellida. Of interest are the suggestions that the order Choristida is in itself a heterogeneous group, and that certain genera now placed in the order Axinellida may in fact be more closely related to the Poecilosclerida.