bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Nature and Formation, of the Spermatophore and Sperm Plug in Carolnus Maenas.
Authors: F. Spalding J. 
Published: April 2021

ABSTRACT
1. The structure of the male reproductive system of Carcinus is described with special reference to the region of formation of the spermatophores and the anatomy of the intromittent organ.
2. The vas deferens produces two fluids, one of these is probably chitin in a fluid form, whilst the other is similar in some respects to the substance forming the general body cuticle, i.e. protein. This substance forms the capsule of the spermatophore.
3. The intromittent organ consists of the modified first and second pleopods and is richly supplied with rosette glands similar to those producing the body cuticle. The ducts of these glands open into the cavity of the first pleopod and their secretion could easily pass with the seminal fluid into the female crab.
4. The female reproductive system is described with special reference to the spermatheca and the cyclical changes occurring in this organ.
5. The sperm plug is composed of two parts distinguishable by their staining reactions. One is similar to the cuticle in its general properties and is probably the product of the rosette glands in the male pleopod. The other is probably chitin formed from its fluid precursor in the seminal fluid of the male crab.
6. It is suggested that the spermatophore of the Brachyura is a degenerate structure having lost its main function, the protection of the sperms during the interval between copulation and egg-laying, in correlation with the development of the internal spermatheca and internal fertilization.
Denticles in fossil Actinopterygii.
Authors: S. Goodrich E. 
Published: April 2021

ABSTRACT
It has long been known that true denticles, as opposed to mere ridges, tubercles, or spines of the outer ganoine layer may occur on the exposed surface of the scales and dermal bones of living Actinopterygii such as Poly pt er us orLepidosteus. But, so far as I know, they have never been described on the scales or dermal bones of any fossil Actinopterygian.1 This is a remarkable fact, for we should certainly expect to find them at all events in the more primitive forms.
Structure and Osmiophilic Inclusions of Astasia harrisii
Authors: Smyth J. D. 
Published: April 2021

ABSTRACTThe general structure of Astasia harrisii Pringsheim is described. The osmiophil material is well shown in Weigl preparations and resists bleaching by hydrogen peroxide or turpentine. In many individuals it consists roughly of an oval mass connected to the reservoir by what is considered to be a canal with osmiophilic walls. The shape of this canal changes considerably, and in many specimens has a blebbed appearance. In others it consists of a number of small osmiophilic vacuoles placed end to end. A small vacuole is often present at the tip of the canal. In a few cases the reservoir is surrounded by an osmiophil cortex continuous with the walls of the canal. It is suggested that the osmiophil material possibly represents the homologue of the Golgi apparatus in higher forms, and is concerned with the secretion or excretion of some liquid down the canal into the reservoir. The possible evolution of the osmiophil material in Astasia is discussed.
Formation and Nature of the Opercular Chaetae of Sabellaria alveolata
Authors: Ebling F. J. 
Published: April 2021

ABSTRACT
The structure of the operculum of Sabellaria alveolata L. is described. There are three fans of chaetae set in each opercular lobe. The chaetae are formed in two longitudinal sacs on each side ; the outer one supplying the outer fan, and the inner the two remaining fans. There is a continual movement of chaetae from the sacs into the dorsal ends of the fans ; they move round the fans and eventually drop out at the ventral ends. The chaetae are secreted by a continuous band of cells moving round the posterior end of the sac and forwards along its ventral side. The nature of the striations at the base of the forming chaeta is discussed. Around this primary core secreted by the basal cell, other cells of the sac secrete a secondary layer. The structure of the fully formed chaeta is described and its two layers correlated with those observed in process of formation. The chaetae are shown to be composed of protein and not chitin. The materials of the outer and inner layers appear to have different iso-electric points.
Studies on the Structure, Development, and Physiology of the Nephridia of Oligochaeta: Part V. The Enteronephric System in Mega-scolex ceylonicus and M. sarasinorum, with remarks on the Phagocytic Organs in Megascolex templetonianus
Authors: Bahl Karm Narayan 
Published: April 2021

ABSTRACT
With the discovery of the enteronephric type of nephridial system in the earthworms Megascolex ceylonicus and Megascolex sarasinorum, this type of nephridial system is now known to occur in the following earthworms: Pheretima—all species. Lampito mauritii and Lampito trilobatus. Woodwardiella bahli. Tonoscolex —all species. Megascolex: (a) Megascolex cochinensis. (b) Megascolex konkanensis. (c) Megascolex ceylonicus. (d) Megascolex sarasinorum. Of these earthworms the best developed system is found in Pheretima, while the most primitive occurs in Megascolex ceylonicus and Megascolex sarasinorum. Megascolex templetonianus does not possess the enteronephric type of nephridial system. Like Acanthodrilus falclandicus, Megascolex templetonianus possesses a pair of well developed ventral phagocytic organs in each segment behind segment XIX, one on each side of the ventral nerve-cord.
Morphology of the Osmiophil Material of Rhabdomonas costata, and its Behaviour during Division
Authors: Smyth J. D. 
Published: April 2021

ABSTRACTIn Rhabdomonas costata Pringsheim the osmiophil material, as shown in Weigl preparations, is very variable in amount and arrangement. In the majority of organisms it takes the form of a large osmiophil body lying beneath the reservoir, to which it appears to be connected by a short osmiophilic canal-like structure. Small scattered osmiophil granules are aggregated in the region of the reservoir and sparsely distributed throughout the cytoplasm. In some individuals the osmiophil ‘canal ‘is absent. The osmiophil body may also be present as a ring with a thickened osmiophil cortex and an osmiophobe centre. The behaviour of the osmiophil substance during division is as follows: the body loses its canal and spreads along the lower wall of the reservoir; as division proceeds it becomes divided into two masses, and when the organism separates into daughter individuals each monad contains nearly equal quantities of the osmiophil substance. There is thus a definite dictyo-kinesisin Rhabdomonas. In a few instances the osmiophil material is carried over whole to one of the two organisms formed by division. In some normal (non-dividing) individuals two osmiophil bodies and their respective canals are found. From the fact that the osmiophil material in Rhabdomonas is demonstrable after the metazoan Golgi Weigl technique, is resistant to bleaching, and is separated out evenly in most cases during division, it is believed to represent the Golgi apparatus in this organism.
The Supposed Pancreatic Organs of Petromyzon fluviatilis and Myxine glutinosa
Authors: Barrington E. J. W. 
Published: April 2021

ABSTRACT
A new description is given of certain structures in Petromyzon and Myxine which, in view of their anatomical relationships and developmental history, have been considered by some earlier workers to be comparable with the pancreas of higher vertebrates.
They are composed of cords of cells which develop, at least in part, from the bile duct. In Petromyzon some of them are shown to be closely associated with a small caecum of the intestine.
They are not externally secreting structures, and in particular they do not in either animal communicate with the intestinal lumen, but there is histological evidence, more convincing in Petromyzon than in Myxine, that they may be endocrine organs.
In both animals secretory cells are present in the intestinal epithelium, and may be considered to represent the zymogen cells of the pancreas. Interpretation of the cords as islet tissue, however, cannot be established on histological grounds alone. Using the Helly-Azan technique, which successfully differentiates the cellular components of the latter in fish, it is shown that only one type of cell is present in the cords ; this does not give the characteristic staining reaction of A cells, and differs in certain respects from the B cells.
The significance of these results is briefly discussed in the light of the evolutionary status of the Cyclostomata.
On the Eyes and Reactions to Light of Proteus anguinus
Authors: Hawes R. S. 
Published: April 2021

ABSTRACT
The structure of the eye has been reinvestigated. Development is arrested at the secondary optic vesicle stage, though growth continues for some time afterwards. The lens does not complete its differentiation; it usually disappears in adult animals, and is replaced by a proliferation of epithelial cells from the iris margin. If the lens persists this proliferation is inhibited. These facts are explicable on the assumption that the normal potencies of the iris margin are realized when the inhibitory action of the lens is removed, but, in Proteus, the typical dominance of the dorsal region of the margin is lost, so that the organization of the proliferated cells into a morphogenetic field does not take place.
The visual cells of the retina stop their development at about the time when rod and cone primordia first become distinguishable.
The optic nerve, greatly reduced, persists throughout life.
The vascular supply to the choroid is maintained through a minute vessel representing the ophthalmic artery.
The relations of the nerve and artery to the trabecula cranii are those of a typical urodele embryo and, in this respect, development in Proteus is arrested at a slightly earlier stage chan in Necturus.
The development of the extrinsic eye muscles is arrested before their adult arrangement is achieved and before the M. rectus internus appears.
The skin above the eye is unmodified and the accessory cornea of Schlampp does not exist.
It is argued that the condition of the eye and some other structures in the orbit is just as much the effect of neoteny as such typically embryonic features as the skin and gills. The general tendency to neoteny was present when Proteus first adopted a cavernicolous life and was able to extend to the organs of vision when their function became unnecessary.
Proteus is sensitive to stimulation by light and responds to it by movement. The eyes are unnecessary for light perception.
Stimulation of the body and tail at any intensity and of the head at low intensities produces slight movements of adjustment and, if repeated, may lead to movements of translation.
Stimulation of the head at high intensities leads to a violent and sudden turning response after a latent period of reaction, dependent, within limits, on the intensity of stimulation.
The active factor of the stimulus is intensity, not direction.
The reactions at high and low intensities and the types of orientations they produce (‘photophobotaxis’ and apparent ‘photokinesis’) are possibly not fundamentally distinct. The subjective impression of movement at random below the threshold for shock reactions is erroneous ; the movements are controlled, but the basis of control has not been discovered.
The light responses are not adaptations developed in relation to life in caves, in which they are never used. They are survivals from a period of epigean existence, and may have played a part in the colonization of caves by Proteus.
The study of Nephridia and Genital Ducts since 1895
Authors: Goodrich Edwin S. 
Published: April 2021

ABSTRACT
From the analysis given above of recent work on the development of the nephridia in the Oligochaeta, it may safely be concluded: that it is now definitely established that the whole nephridium from funnel to pore (including the whole nephridiostome, the excretory canal, the bladder and duct to the exterior, but excepting an insignificant ingrowth of epidermis at the pore in higher forms), arises from a special cell, the nephridioblast; that the nephridioblast does not belong to the coelomic epithelium, is not derived from the coelomesoblastic band, but is of retroperitoneal origin, primitively occupies an intersegmental position, and only breaks through the coelomic epithelium at the point where the nephridiostome comes to open (Text-fig. 79).
Further, it is exceedingly probable, though not so definitely proved, that such nephridioblasts are derived in the higher Oligochaeta (Megadrili) from nephric bands or rows of cells formed by the repeated forward division of posterior nephric teloblasts situated at first in the surface layer of ectoblast ; or, if not from regular bands, at all events from originally superficial cells of ectodermal or ectomesodermal nature.
Usually, and possibly always, the nephridial canal develops as a string of cells, produced by the repeated backward division of the nephridioblast, which string becomes hollowed out by an intracellular lumen. The nephridiostome is formed by the division of the residual nephridioblast itself, though some of the must anterior cells of the string may contribute to it.
In this connexion it must be remembered that, like the larval protonephridia of the Polychaeta, the larval nephridia of the first segment in Oligochaeta appear certainly not to be developed from the coelomesoblast, but from ectoblastic or ectomesoblastic cells (cells 2c in Bimastus, according to Svetlov (1928)). They appear very early and in Tubifex even before the coelomesodermal teloblast has begun to divide (Ivanow, 1928). It may be concluded that, as long ago maintained by Vejdovsky, neither the embryonic nor the later nephridia are derived from the coelomesoblast.
The Study of Nephridia and Genital Ducts since 1895
Authors: Goodrich Edwin S. 
Published: April 2021

ABSTRACT
In 1895 a general review of the morphology of nephridia and genital ducts, and their relation to each other and to the coelom, was published by me (Goodrich, 1895). The present paper is a similar review of the work done since that date on these organs throughout the Metazoa Triploblastica. It is shown that a great many newly discovered facts support the conclusions put forward in 1895, notably the conclusion that two different organs of independent origin—genital ducts and excretory nephridia— can be traced through the various Phyla of Triploblastica. The Gonocoel theory is accepted as the best explanation of the origin of the coelom. In all the various groups coelomoducts, primitively acting as genital ducts, are shown to be derived from the epithelial wall of the gonadial sac, or its derivative the coelomic sac, as centrifugal outgrowths which meet the ectoderm and come to open to the exterior ; whereas the excretory nephridia are to be derived from superficial rudiments, often in the form of nephridioblasts, which develop centripetally, and give rise to the whole nephridium whether protonephridial or metanephridial. The nephridial rudiments are not developed from the coelomesoblast, but are either of ectodermal or of ecto-mesodermal origin. The coelomoducts are always of coelomesoblastic origin. In some Polychaeta (and possibly some Archiannelida) nephridium and coelomoduct may combine to form a nephromixium of both excretory and genital function. In many groups some of the coelomoducts may secondarily acquire an excretory function. In such groups nephridia may disappear, or be no longer developed; provisional larval nephridia may, however, persist until the excretory coelomoducts are developed.
Suggestions for the improvement of the nomenclature of these organs and their specialized modifications are made (pp. 117,119). Incidentally many new unpublished observations on their structure and development are recorded. More particularly may be mentioned the early development and morphological relations of the nephridioblast in Tubifex (p. 271).
The Anatomical Memoirs of John Goodsir, F.R.S.
Authors: Turner W. 
Published: April 2021

ABSTRACT
The name of John Goodsir is not, perhaps, so familiar to microscopical observers as that of many others who have done less service to science by the aid of the microscope. The fact is, the late Professor in Anatomy-prosecuted his researches in anatomy and physiology from a very exalted point of view, and the microscope was only used by him, as it always ought to be used, as a means of observation subservient to the higher-generalizations of biological science. At the same time these memoirs abundantly show that the microscope was one of the most frequent instruments employed in his anatomical and physiological researches. One of the earliest memoirs in these volumes is that on “The Development of the Pulps and Sacs of the Human Teeth; “and although not an exclusively microscopical subject, he could not have carried on his researches on this subject or have arrived at his conclusions without the aid of the microscope.
On Draparnaldia Crdciata, Hicks
Authors: Braxton Hicks J. 
Published: April 2021

ABSTRACT
The Draparnaldia, of which a drawing for the first time is now given, was described by me in the ‘Journal of the Linnæan Society,’ November 18th, 1857. It was discovered by me in the gentle streams issuing from the bogs of the New Forest in several localities. Subsequently, among some drawings sent to me by Mr. G. S. Brady, Secretary of the Tyneside Naturalist Field Club, in order to be named, I was pleased to find a very accurate representation of this alga. It was found by him in the peat bogs near Crag Lough, Northumberland, and is mentioned by him, along with others found in the same locality, in the sixth volume of the ‘Trans. Tyneside Naturalist Field Club.’
Spermatophore Production in Rhodnius prolixus
Authors: Davey K. G. 
Published: April 2021

ABSTRACT
On the basis of experimental and histochemical evidence it has been shown that the main body of the spermatophore of Rhodnius is a mucoprotein or neutral mucopolysaccharide originating in the transparent accessory glands of the male. A study of the events during copulation demonstrated that the spermatophore is formed inside the spermatophore sac, the folded terminal portion of the intromittent organ. Normally folded inside the base of the penis, the spermatophore sac is everted by the influx of the transparent secretion and acts as a mould for the spermatophore. The solidification of the fluid, transparent secretion inside the sac is the result of a lowering in pH brought about by the secretion of the bulbus ejaculatorius.
A Histochemical Investigation of the Pituitary Glands of some Teleost Fish
Authors: Matty A. J. , Matty J. M. 
Published: April 2021

ABSTRACT
Some histochemical observations on the pituitaries of three marine and three freshwater teleost fish have been made. It has been shown that cells of this gland, which are stained identically in different species by Azan, do not always give identical histochemical reactions, and that in the same species cells which after histological staining have similar tinctorial affinities may be differentiated histochemically. These observations are discussed with regard to the function of the gland.
The Action of Fixatives on the Unmasking of Lipid
Authors: Clayton Blanche-P. 
Published: April 2021

ABSTRACT
The capacity of various primary (unmixed) fixatives to split lipids from lipoprotein complexes was investigated. The lipoproteins that formed the test-objects of the research were those contained in (a) the acroblast of the cricket (Acheta domesticus), and (b) the endoplasmic reticulum (‘ergastoplasm’) of the acinar cell of the pancreas of the laboratory mouse. The two test-objects gave essentially the same results. Of the 16 compounds tried, cadmium chloride is the most powerful unmasker of lipids. Mercuric chloride is also a powerful unmasker, and gives much better fixation. Chloroplatinic acid and formaldehyde are moderately powerful unmaskers.
The Nature of a Chromosomal Phospholipid
Authors: Chayen J. , Gahan P. B. , Cour L. F. LA 
Published: April 2021

ABSTRACT
It has been found that the heterochromatic region of interphase nuclei of plant roots and calf thymus, fixed in formaldehyde solution, do not stain for phospholipid as they do after Lewitsky’s fixative. It has been shown that this is probably due to the extraction of a protein-phospholipid complex. Some lipid-like material has been purified from the used formalin and shown to contain glycerophosphate. The nature of the association between the lipid and protein is discussed.
The Histology of the Nervous System of an Insect Rhodnius prolixus(Hemiptera): II The Central Ganglia
Authors: Wigglesworth V. B. 
Published: April 2021

ABSTRACT
The central nervous system of Rhodnius has been studied in sections stained with osmium / ethyl gallate. The single type of glial cell responsible for perineurium and axon sheaths in the peripheral nerves becomes differentiated in the thoracic ganglia into four types.
Type i cells form the layer of perineurium cells filled with filamentous mitochondria. These cells which are rich in succinoxidase control the passage of all substances to and from the ganglion.
Type ii cells produce the thick myelin-type sheaths for the lateral group of motor axons (see below).
Type iii cells, the giant glial cells in the ganglionic layer, have a very extensive cytoplasm which sends deep tongue-like invaginations into the large ganglion cells. This cytoplasm must control the transmission of nutrients and excretory substances to and from the neurones. It contains some non-specific esterase.
Type iv cells form an investment of the neuropile. They also have extensive cytoplasm which surrounds the axons and dendrites and provides intensely staining inter-neuronal material in the synaptic regions. This material, the ‘darkly staining neuropile’, is the chief site of acetylcholine esterase.
The nerve-tracts are well displayed by the osmium / ethyl gallate method. The axons appear as unstained cords containing mitochondria, against the dark neuropile. The large motor axons of the legs separate into two groups. The medial group run directly into the neuropile and have thin sheaths. The lateral group remain outside the neuropile; they become narrow and enclosed in a thick myelin-type sheath; but as they turn into the neuropile the sheath becomes thin and the axons enlarge again.
The Histology and Activities of the Tube-feet of Echinocyamus pusillus
Authors: Nichols David 
Published: April 2021

ABSTRACT
The histology of the suckered, buccal sensory, and respiratory tube-feet and their ampullae, where they occur, of the clypeasteroid sea-urchin Echinocyamus pusillus is described. Each suckered tube-foot possesses two sets of special muscles for attachment and detachment, a ring of mucous glands to assist in attachment, and a ring of sensory cilia. The stem retractors are in four columns, whose differential contraction provides the means of postural movement relative to the test. The ampullae of these tube-feet are exceedingly thin-walled, apparently musculo-epithelial, with anastomosing contractile elements. The canal between tube-foot and ampulla contains a swollen coelomic epithelium which may help to maintain the nerve relationships of the system. The activity of the suckered tube-feet is compared with that of the tubefeet of the starfish, Asterias rubens. The buccal tube-feet, larger than the suckered tube-feet, have large disks underlain by a thick nerve plexus supported by transverse fibres ; a ring of sensory cilia surrounds the disk. They have no mucous glands and no suckers, and are presumably entirely sensory, probably both tactile (the cilia) and chemoreceptive (the disk). The respiratory tube-feet are thin-walled sacs, the walls consisting of an outer ciliated and an inner non-ciliated (coelomic) epithelium with cross-connexions for support; where the coelomic epithelium lines the pair of canals through the test it is heavily ciliated. In the specializations of its tube-feet this urchin is shown to share some features with the regular urchins and others with the spatan-goids.