bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Points in the Development of Neomysis vulgaris
Authors: Needham A. E. 
Published: April 2021

ABSTRACT
Certain muscle systems, alleged to be ectodermal in origin in Hemimysis, appear to be mesodermal in Neomysis. They are: The extensor and flexor muscles of the limbs. The carapace fold muscles of the maxillary and thoracic 1,2, 3 segments. The interparagnath muscle. There is no clear indication of cellular ectodermal tendons. Evidence is given that the liver is of endodermal origin and derived from the yolk-pyramids in Neomysis. The telson mesoderm appears to be derived from that of the last (7th) abdominal segment, there being no post-segmental mesoderm in Neomysis. The median dorsal organ may be an important agent in the hatching processes. Later it draws in and resorbs the superfluous extra-germinal ectoderm. The dorso-lateral organs probably correspond to the ‘tegumental glands’ of adult Crustacea. During one phase of its development the gonad of Neomysis sometimes shows a restricted metameric segmentation.
Studies on the Cultivation of Pieces of the Mantle of Modiolus modiolus
Authors: Gresson R. A. R. 
Published: April 2021

ABSTRACT
Pieces of the mantle of Modiolus were sterilized by means of ultra-violet light, and cultivated, by the hanging drop method, in sea-water, and in sea-water plus tissue extract. An outwandering of amoebocytes takes place shortly after the preparations are made; this is followed by an outgrowth from the epithelium which secretes the shell. Three types of epithelial cells are present in the outgrowths. Undoubted stages of mitosis or of amitosis were not observed amongst the epithelial cells. The shell epithelium often becomes folded so that hollows are present on the surface of the explant. The cells at the margin of the folds become elongate and tend to grow over the hollows. The amoebocytes, by means of membranous expansions of the ectoplasm and fine pseudopodial-like processes, undergo movements and change of shape. Clumped and necrotic cells are rounded. Hyaline and finely granular amoebocytes, due to their phagocytic action, become filled with granules, vacuoles, and large deeply stained bodies. The amoebocytes often form a loose network in the medium. Stages of mitosis or of amitosis were not observed, but amoebocytes with double nuclei were present in some of the preparations.
The Posterior End of Meckel’s Cartilage and related ossifications in Bony Fishes
Authors: Haines R. Wheeler 
Published: April 2021

ABSTRACT
In modern Dipnoi (Protopterus) the membrane bones are separated by connective tissue from Meckel’s cartilage, and there is no endochondral or perichondral bone. The cartilage grows evenly over its whole extent. In Polypterus a large articular ossifies the posterior end of the cartilage, including the retro-articular process, and spreads into the neighbouring connective tissues. In Elops the joint surface is carried partly by the articular, and partly by the retro-articular, a special ossification of the retro-articular process. In most teleosts (Mugil, Sardina, Trigla) the articular is absent and the angular invades the perichondrium and cartilage to form the joint surface. Special growth zones of flattened cells are formed in the cartilage which by their growth carry the retro-articular, angular, and dentary away from one another, stability of the jaw being maintained by new growth of the membranous parts of the bones. Endochondral bone is reduced or absent in some specialized fishes (Tetrodon, Notopogon). The sesamoid articular of teleosts is a separated part of the angular which gives insertion to the adductor mandibulae muscle. An attempt is made to follow the evolution of Meckel’s cartilage and the related ossifications by a comparison of the early Dipnoi, Crossopterygii, and Amphibia described in the literature with modern forms.
The Reproductive System of the Planarian Artioposthia triangulata (Dendy)
Authors: Fyfe Marion L. 
Published: April 2021

ABSTRACT
The main subject of this paper is a detailed description of the reproductive organs of a planarian initially described by Dendy as Geoplana triangulata. Five unusual features are observed in the reproductive system:
The vas deferens consists of a series of wide convoluted branching tubes extending from the region of the mouth to the anterior end of the seminal vesicle. The penis is very small and inconspicuous. The atrium masculinum is provided with three pairs of muscular gland-organs or adenodactyli. The paired ovaries are situated one on each side of the seminal vesicle, not in the region of the brain as is usual. Each ovary is a long fusiform body enclosing more than one true ovary or germarium, as well as specialized parovarian and amoeboid cells which are probably nutritive, and are associated with the internal opening of the oviduct.
The writer refers Geoplana triangulata Dendy to the genus Artioposthia owing to the presence of adenodactyli in the atrium masculinum. Each adenodactylus encloses a glandular reservoir from which a ciliated duct leads to the atrial cavity. The actual function of the adenodactyli is obscure, hut the very small size of the penis and the fact that the adenodactyli are extrusible suggests the possibility of these latter performing the function of a penis.
On the Ciliary Mechanisms and Interrelationships of Lamellibranchs.: PART V: Note on the Gills of Amussium pleuronectes
Authors: Atkins Daphne 
Published: April 2021

ABSTRACT
The gills of Amussium pleuronectes L., a species from shallow water, were examined and the lamellae found to he plicate and heterorhabdic, thus differing in structure from those of the deep-water species, Amussium dalli, Amussium meridionale, and Amussium lucidum, which Ridewood found to have flat and homorhabdic lamellae. The gills of Amussium pleuronectes closely agree with those of the Pectinidae also possessing plicate and heterorhabdic lamellae.
Ridewood’s classification of the Amussiidae with the Mytilacea cannot be upheld; the position of this family is with the Pec-tinacea as in Pelseneer’s classifications of 1888, 1906, and 1911.
An Account of Amoeba discoides; its Culture and Life History
Authors: Hayes Catherine 
Published: April 2021

ABSTRACT
A large free-living amoeba found by Mr. Harry Watkinson in the tropical fish tanks of Mr. Albert Sutcliffe of Grimsby has been identified as Amoeba discoides (Schaeffer, 1916) = Metachaos discoides (Schaeffer, 1926). From the inoculation material obtained from these tanks Amoeba discoides has been successfully cultivated in the Notre Dame Training College Laboratory by a technique similar to that used for the cultivation of Amoeba proteus: wheat being the pabulum employed. In contrast to what obtains in the cultivation of Amoeba proteus, however, Amoeba discoides flourishes more luxuriantly in shallow Petri dishes, than in deeper troughs. The nucleus in the resting and dividing stages is described; division is amitotic. The more important cytoplasmic contents, including nutritive spheres, and crystals are likewise described. The life-history has been worked out. The adult amoeba becomes an agamont giving rise to agametes which eventually grow into adult amoebae, the life-cycle occupying roughly about four months. Descriptions of the nucleus of the newly hatched and developing amoebae are deferred.
Polymastigote flagellates of the genus Foaina Janicki, and two new genera Crucinympha and Bullanympha
Authors: Jun Harold Kirby 
Published: April 2021

ABSTRACT
1. Foaina gracilis does not have two parabasal bodies, as described by Janicki, but a single structure that partially encircles the nucleus and extends on both sides of the blepharoplast. It is the type species of a large genus of Devescovininae.
2. A similar flagellate, Foaina delicata new species, occurs in Glyptotermes iridipennis. It was included by Duboscq and Grasse in the supposed life-cycle of‘Devescovina hilli’ as a young stage.
3. The larger forms typical of ‘Devescovina hilli’ do not belong in the genus Devescovina. A new genus, Crucinympha, is established.
4. The parabasal apparatus is very different from that of species of Devescovina. There is a proximal element bent in a hook on the anterior surface of the nucleus, with the blepharoplast closest to the bend, passing along the nuclear membrane in a C- or U-form; and one or two, rarely three, distal elements attached to this so that the apparatus has the shape of an inverted T or a cross.
5. The supposed longitudinal fission of the parabasal apparatus of ‘Devescovina hilli’, described by Duboscq and Grasse, is not actually division; its description was due to misinterpretation of the normal structure.
6. A remarkable flagellate, Bullanympha silvestrii new genus, new species, is present in Neotermes erythraeus.
7. The parabasal apparatus of Bullanympha silvestrii is very unusual. It consists of a U-shaped proximal element of normal size and form comparable to the parabasal bodies of certain species of Foaina, and a voluminous, compressed, distal element attached to this at the bend and turned around the axostyle to times, having a form suggestive of a spiral, sloping shelf.
8. Tn the surface layer of cytoplasm of the whole body of all specimens are numerous, short, rod-shaped, deeply staining peripheral granules. Some show forms suggesting fission, and they are probably intracytoplasmic micro- organisms.
The Structure of the Golgi Apparatus in the Tissues of Amphibia
Authors: Pollister Arthur Wagg 
Published: April 2021

ABSTRACT
The Golgi apparatus has been studied in nearly all tissues of larvae and adults of a number of Amphibia. In every case the apparatus is lamellar in structure. In all epithelia, except the simple squamous and the specialized cells of the liver and peptic glands, the Golgi apparatus approximates the form of a vertical collar, most commonly encircling the distal part of the nucleus and projecting into the distal end of the cell. In leucocytes and fibroblasts the Golgi apparatus takes the form of a horizontal collar near the approximate centre of the main cytoplasmic mass. The Golgi apparatus of smooth muscle-fibres and of myocardium is developed from the condition in leucocytes by elongation of the ring. The apparatus is greatly extended throughout the central region of the cytoplasm in cartilage and bone cells, and in odontoblasts; and in these types there is a condition where the width of the Golgi plates approximates the thickness, resulting in a filamentous structure. In nervecells of the spinal cord and medulla, and in the smaller nervecells of cranial, spinal, and sympathetic ganglia, the Golgi apparatus is in the form of a single complex plate-work. In large cranial ganglionic cells of larvae the apparatus consists of a considerable number of separate platelets.
Measurements of the lamellae that are the basis of structure of the Golgi apparatus, in all types of cells of all animals studied, shows that the thickness is very uniform, approximating 0-2 micron, regardless of the shape of the apparatus as a whole. Data on the form of the apparatus, and on the mode of distortion of the lamellar structure when the cell shape is altered by pressure, indicate that the lamellae have the properties of an elastic solid.
On the basis of orientation of centrioles and Golgi apparatus all cells of Amphibia that have been studied may be assigned to one of two groups: A, the epithelial, or physiologically polarized type; or B, the leucocyte, or physiologically unpolarized type.
On the Mantle Cavity and its Contained Organs in the Loricata (Placophora)
Authors: Yonge C. M. 
Published: April 2021

ABSTRACT
The course of the water currents in the mantle cavity of three species of the Chitonida, and one species of the Lepidopleurida, has been determined. Inhalant openings are created anteriorly or laterally by local raising of the girdle. The single exhalant opening is always posterior and confined to the region between the last pair of gills. The exhalant current carries with it the genital and excretory products, and, in the Chitonida, the faeces. The bridging of the pallial grooves in the region of the girdle folds by the post-renal gills (and adanal gills in the Lepidopleurida) completes the functional division of the pallial grooves into inhalant and exhalant chambers. The gills possess the typical structure of ctenidia, and their (filiation is a modification only of that of ctenidia. They are to be regarded as multiplied ctenidia and not as secondary structures. The individual filaments are shortened, attached to those of adjacent gills by long interlocking cilia, and have a broad band of lateral cilia which create the respiratory current. Four possible tracts of mucous glands in the palliai grooves are concerned with the consolidation of sediment. The palliai tracts may be homologous with the hypobranchial glands of the Prosobranchia; all are analogous with these. In the Chitonida sediment is rejected only from the exhalant chamber, in the Lepidopleurida mainly from the inhalant chamber. Osphradia,possiblyhomologouswiththoseinthe Gastropoda, occur in the majority of the Chitonida. With them may be associated anterior sense organs. In the Lepidopleurida they are replaced by branchial and lateral sense organs. AH are similar in structure and innervation. They have been considered olfactory in function, but with equal reason may be regarded as tactile organs concerned with the estimation of sediment. The Loricata probably evolved between tide-marks, their characteristic structure being admirably adapted for life on the shore. The reasons for the differences between the structure and habits of the Lepidopleurida and the Chitonida are discussed.
Studies on the Structure of the Golgi Apparatus. IV. Endostyle of Branchiostoma indicum.
Authors: Subramaniam M. K. 
Published: April 2021

ABSTRACT
The work on Branchiostoma was undertaken with a view (1) to study the relation between the centi J and Golgi apparatus in a ciliated cell where the parts of the central apparatus are supposed to be associated with the cilia, and (2) also to see whether any hint as to the mode of evolution of the network can be obtained.
Each group of mucous secreting cells seems to be in a particular stage of activity. The variations in activity between the individual cells in a particular group is very small. It was observed that generally, while two groups of gland-cells are loaded with mucus, the other two are at the beginning of the secretory cycle.
The mitochondria, which appear as a few large grains in the cells at the beginning of secretory activity, break up into small granules before mucous droplets put in their appearance. Most of these mitochondrial granules are extruded with the mucus.
The Golgi apparatus occurs as a few small grains having an indefinite distribution. There is no ‘Golgi zone’, nor are these elements collected around a centriole. These increase in size and number and as they do so in many of them the central area becomes brownish. The Golgi elements finally get scattered through the cell. This scattering is soon followed by the appearance of mucus in the chromophobic areas of the elements. Increase in size of secretion droplets leads to rupture of the osmiophilic portion in regions where it is thin, and mucous globules with Golgi caps may be seen in the cytoplasm. Most of the Golgi elements degenerate, and those left behind apparently become reorganized for the next secretory cycle.
Examples and results are cited to show that the chromophobic part has nothing to do with the centrosphere. It appears difficult to decide whether the presence of Golgi apparatus in the form of discrete elements is the retention of an invertebrate characteristic by Branchiostoma.
The recent conclusions of Hirsch and Duthie are discussed, and it is shown that unless equal importance is given in future studies to the shape and structure of the Golgi apparatus and mitochondria as is at present given to the function of these cytoplasmic components we cannot accept the claims put forward by these authors. There appear to be exceptions to every rule, and in order to accept these as exceptions critical evidence is necessary.
The Alimentary Canal and Pro-epithelial Regeneration in Coccinella septempunctata with a comparison of Carnivorous and Herbivorous Coccinellids
Authors: Pradhan S. 
Published: April 2021

ABSTRACT
The paper incorporates: The anatomy of the alimentary canal of Coccinella septempunctata as a type of carnivorous Coccinellid.A detailed account of the extrinsic musculature and the nerve-supply of the cephallic stomodaeum, which have been studied in very few insects and never in Coccinellids.The histology of the alimentary canal, specially the midgut, distinguishing four definite types of epithelium, one of which is surprisingly peculiar and has not been described before. This type of epithelium shows apparently two layers of cells, one superimposed over the other, the outer having large, regularly arranged, intercellular vacuoles as have not been described before, at least in the gut of insects.A discussion on the relations of the four types of epithelium to one another, recognizing that this peculiar type of epithelium is just a phase in a unique process of Pro-epithelial Regeneration in the mid-gut epithelium.A comparison of the chief characteristics of the alimentary canal of carnivorous and herbivorous Coccinellids based on the study of seven species of lady-bird beetles.Probable explanations of the differences between the alimentary canals of the carnivorous and herbivorous Coccinellids.
A Cytological Study of the Centrifuged Oocyte of the Mouse
Authors: Gresson R. A. R. 
Published: April 2021

ABSTRACT
The ovaries of the mouse were ultra-centrifuged at a force of about 130,000 times gravity. The young oocyte is stratified into three layers: lightly stained cytoplasm, usually containing a few small granular Golgi elements, in the centripetal end of the cell; a middle layer of Golgi elements containing the nucleus; a centrifugal layer of mitochondria. In the larger oocytes a thin layer of yolk is present between the Golgi layer and the centripetal pole, while a layer of nongranular substance is present at the centrifugal pole. The mature oocyte is stratified into four layers: a lightly stained centripetal layer; a layer of yolk; the Golgi layer; a centrifugal layer of mitochondria. The Golgi layer is now divided into two parts; the centrifugal part contains numerous mitochondria amongst the Golgi elements. The nucleolar material is the heaviest substance in the nucleus; it increases in density with the growth of the egg. In the mature oocyte the nucleus lies in the mitochondrial layer; the nucleus is thrown towards the centrifugal pole by the weight of the nucleolus. The Golgi elements are in the form of granules, rods, and of irregularly shaped bodies. It is probable that the localized Golgi material of the mouse egg is not in the form of a network. Fat was not identified in the normal ovarian eggs, but is present in degenerating ova. The Golgi elements give rise to the fat of degenerating eggs. The inclusions and components of the follicle-cells were not always affected by the force necessary to bring about stratification of the oocyte. The degenerating eggs were not stratified.
The Golgi Apparatus and Pyrenoids of Chilomonas paramecium, with remarks on the Identification of Copromonas subtilis
Authors: Gatenby J. Brontë , Smyth J. D. 
Published: April 2021

ABSTRACT
In Chilomonas paramecium the contractile vacuole is surrounded by a cortical substance (Golgi apparatus) which has the power of reducing osmium tetroxide solution and thus impregnating black (Nassonow). This cortex blackens thus in over 99 per cent, of individuals in a culture which has not been dividing. In a culture in which the individuals have been rapidly dividing, the percentage of unimpregnated contractile vacuoles increases considerably, up to about 5 per cent. During division of Chilomonas in about 70 per cent, of cases the osmiophile substance is very equally divided between the daughter cells. The dividing cortex comes away from the contractile vacuole, which eventually collapses, new contractile vacuoles arising in the site of the divided osmiophile material. In about 25 per cent, of division stages osmication of the cortex fails to a greater or lesser degree. There is always a very distinct tendency for this failure to take place even in the best of preparations. In some cases (about 3 per cent.), during division, the entire contractile vacuole and its cortex goes over whole to one individual. A new vacuole, apparently without cortex, arises spontaneously in the other individual. It is unlikely that all of these cases are due to failure of impregnation in one of the individuals, though this possibility cannot be ruled out completely. The behaviour of the original contractile vacuole cavity before separation of the daughter cells is as follows. The lipoid, having partially retreated from the vacuole, becomes separated into two parts, and the centrally placed vacuole disappears (figs. 4 and 6, Pl. 36; figs. 10 and 15, Pl. 37). New vacuoles appear in the site of the lipoid bodies in each daughter cell (fig. 5, Pl. 36). Two ellipsoidal accessory bodies or pyrenoids lie on a level with the vestibule. In older cultures the two bodies are often exactly the same size and colour (corrosive osmic followed by neutral red or haematoxylin), but in rapidly dividing cultures, one body may be of normal size, whereas the other may be absent or much smaller. During cell division, one body is carried across to each daughter. No exception to this was ever found. Identification of the smaller Peranemidae is in a confused state. Probably several species, and possibly even genera, have been described by various authors as S cy t o mon as (Copromonas) subtilis.