bluuebunny/crossref_metadata_2025_split huggingface dataset:
On Certain Features in the Development of the Alimentary Canal in Lepidosiren and Protopterus
Authors: Kerr J. Graham 
Published: April 2021

ABSTRACT
The fore-gut first becomes folded off from the main mass of yolk-cells. The pyloric valve arises by the hind end of the fore-gut being pushed back into the cavity of the mid-gut. The main mass of yolk-cells becomes gradually “modelled” into a spirally-coiled intestinal rudiment. The main part of the buccal lining is developed in situ from large yolk-cells. The part of the ventral side of the head, on which are the olfactory rudiments, becomes enclosed in the buccal cavity by the development of the upper lips and by the forward growth of the lower jaw. The olfactory opening becomes divided into anterior and posterior nares by the apposition and fusion of the intermediate portion of its lips. The thyroid arises as a solid downgrowth from the buccopharyngeal floor, which gradually becomes cut off from behind forwards. The tongue is a primary tongue like that of Urodeles, but without gland-field. The lung arises from a solid mid-ventral rudiment. When the lung becomes bilobed, the (actual) right lobe is for a time small in size as compared with its fellow. Complicated torsional processes take place during the development of the lung. Through the dorsal mesentery becoming partially merged in the splanchnocœle roof, the lungs come to lie outside the snlanchnocœle. The general facts of lung development go to support the view that the lung of Polypterus shows a persistence of the condition ancestral to that of Dipnoi and Actinopterygii. The pancreas arises from a dorsal and two ventral rudiments.
The Eye of Pecten
Authors: Dakin W. J. 
Published: April 2021

ABSTRACT
The first reference to the eyes of Pecten that I have been able to find is that of Poli in 1795. Since that date more than a score of investigators have studied these small Organs and treated in more or less greater detail the histology. Each has made new discoveries, which have in very many cases been refuted by their immediate successors, to such an extent, in fact, that it was almost impossible to determine from the literature on the subject the truth in regard to certain parts. One of the last and most reliable papers was that of Hesse, published in 1900 (34). He pointed out that some points were still unsolved (though adding one or two discoveries himself), and that the success of the methylene-blue method, if attained, would possibly elucidate all.
A Study of the Blood of certain Coleoptera: Dytiscus marginalis and Hydrophilus piceus.
Authors: Barratt J. O. Wakelin , Arnold George 
Published: April 2021

ABSTRACT
The present investigation had its origin in a study of the cell changes occurring in malignant growths, during the course of which attention was directed towards the presence of wandering cells in such growths. It appeared likely that light would be thrown upon the morphology and life-history of the wandering cells of the higher vertebrates by comparison with the free cells of the blood of various invertebrates. To this end the present investigation, which is confined to Coleoptera, was undertaken. The work, however, extended beyond the limits originally assigned, for it became necessary, partly in order to prepare an isotonic fluid for the blood-cells studied, and partly in order to determine the nature of the medium in which they lived, to examine the fluid part of the blood also.
Studies in the Experimental Analysis of Sex
Authors: Smith Geofirey 
Published: April 2021

ABSTRACT
In Part 5 of these studies (‘Quart. Journ. Micr. Sci.’ vol. 56, pt. 3, 1911, p. 591) some observations on the fluctuations in size of hens’ combs were recorded, which showed that in adult as well as in young hens the area of the comb may increase or decrease with great rapidity, the greatest increase recorded being 130 per cent, within three weeks. It was proved that these striking fluctuations were independent of any experimental treatment, that they did not correspond with a general increase in weight, and that they appeared to coincide with the egg-laying periods.
The Reproductive Cycle in the Marsupial Dasyurus viverrinus
Authors: Hill J. P. , O’Donogliue Chas. H. 
Published: April 2021

ABSTRACT
In recent years a great deal of attention has been paid to the reproductive processes in the Mammalia, and in particular to the phenomena connected with the œstral cycle. Observations relating to the latter, however, have been almost entirely based on Eutherian mammals, and, indeed, largely on Primates (Heape (8, 9, 10), Van Herwerden (12), Hitschmann and Adler (15), and others) and various domesticated or semi-domesticated Eutheria (e.g. sheep (16), dog (19), ferret (17), Marshall). Having at our disposal a large volume of records relating to the -breeding habits of Dasyurus, as well as an abundant supply of material, we have thought that an inquiry into the reproductive cycle in this member of the Marsupialia (in many respects a more primitive group than the Eutheria), might not only be of interest, but might, perchance, throw light on some of the problems relating to the Eutherian œstrous cycle which still await solution. We venture to hope that the account of the reproductive cycle which we are now able to present will be found to fulfil, in some measure, expectations in this latter regard.
On Acrossota liposclera, a New Genus and Species of Alcyonarian with. Simple Tentacles
Authors: Bourne Gilbert C. 
Published: April 2021

ABSTRACT
The Alcyonarian Colony to be described in the following pages was collected by Prof. A. Willey in the d’Entrecasteaux group of islands, British New Guinea, and sent to me, I am ashamed to say how many years ago, along with a collection of Actiniae and Zoantheae. Partly because of the difficulty and uncertainty of identifying spirit preserved actinians, partly because I had turned my attention to another group of animals, I have neglected this collection until, a short time ago, I began to prepare such specimens as were suitable for cutting into sections with a view of identifying and describing them. Among the Zoanthem I found a colony of small translucent polyps apparently growing in a bunch attached to the fronds of a species of Halimeda. Some of these polyps were partly expanded and exhibited a few simple digitiform tentacles, and this character, together with their general appearance, suggested that they were non-incrusted Zoanthids. On closer examination I found that the polyps arose at intervals from a long, sparsely branched adherent stolon, and that the apparently single colony consisted of several such stolons so closely intertwined that the polyps arising from them were closely bunched together, giving the deceptive appearance of a compact encrusting colony. And, as I shall describe in detail, I found that the tentacles, though simple fingershaped structures, are always eight in number, and that the structure of the polyps, in almost all other respects, presents the well-known characteristic Alcyonarian features.
The Chromosome Complex of Culex Pipiens
Authors: Taylor Monica 
Published: April 2021

ABSTRACT
The somatic number of chromosomes is three, both in the male and female of Culex pipiens. The number of chromosomes in the spermatogonia as well as in the primary and secondary spermatocytes and spermatids is three. The spermatogonial cells are not characterised by a synizesis stage, which latter stage marks off the spermatogonial from the spermatocyte I stage. The nuclear membrane persists throughout mitosis. The synizesis stage represents an inactive phase of the nucleus in spermatogenesis. A synizesis stage occurs in somatic nuclei.
The Embryonic Area and so-called “Primitive Knot” in the Early Monotreme Egg.
Authors: Wilson J. T. , Hill J. P. 
Published: April 2021

ABSTRACT
Since the appearance, in 1906, of our “Observations on the Development of Ornithorhynchus” (1) there have appeared for the most part only isolated comments upon the facts there set forth and on our interpretation of them. This is doubtless owing to the absence or the extreme rarity of such material as might serve as a reliable basis for criticism of our results.
The Larva of the Starfish Porania pulvillus (O.F.M.)
Authors: Gemmill James F. 
Published: April 2021

ABSTRACT
In its general outlines the larval history of Porania resembles that of Asterias rubens, L., recently described by me in a paper (7), to which reference may be made throughout the following, for data regarding corresponding stages and structures in the development of other Asterids. The methods employed in order to obtain the larvæ were the same as in the case of A. rubens (7, p. 224), the fertilisations being made at the Millport Marine Biological Station, and the rearing carried out in the Embryological Laboratory at Glasgow University.
The Homologies of the Muscles related to the Visceral Arches of the Gnathostome Fishes
Authors: Allis Edward Phelps 
Published: April 2021

ABSTRACTIn 1874 Vetter published his well-known work on the muscles related to the visceral arches of the Selachii, and, clothed somewhat with Gegenbaur’s authority, it immediately became the recognised standard of reference, and all later work relating to the subject has apparently been greatly influenced by it. Certain parts of Vetter’s descriptions have, however, always been to me obscure, but I have attributed it to my not being personally familiar with the anatomy of the Selachii. Considering that this familiarity had been in a measure acquired by my present work on the cranial anatomy of Chlamydoselachus, I recently carefully re-read Vetter’s descriptions, but I still found the particular parts referred to neither precise nor clear. Tiesing’s (1895), Ruge’s (1897), and Marion’s (1905) later works not helping to a proper comprehension, I then had recourse to dissections of such few specimens of the Selachii, other than Chlamydoselachus, as I had at my disposal. The result has been to lead me to consider the particular parts referred to, in the several works above mentioned, incorrect, and it has also unexpectedly led me to seriously question every one of the several instances cited by Edgeworth (1911) in which one of these visceral-arch muscles of fishes is said to be innervated, in the adult, by the nerve of a segment of the body other than that from which the muscle itself is developed.
Note on Eggs and Embryos of the South African Myxinoid, Bdellostoma (Heptatretus) hexatrema, Müll
Authors: Gilchrist J. D. F. 
Published: April 2021

ABSTRACT
The problem of the exact relationship of the Cyclostomes to Amphioxus on the one hand and the Gnathostomes on the other has been rendered more difficult of solution on account of the lack of knowledge of the early stages of the Myxinoids. While the Lampreys have been very thoroughly investigated in this respect, there remains some considerable obscurity with regard to the details of the development of the Hagfishes. Of the two chief genera, Myxine and Bdellostoma, embryological material has only been procured iu the-case of the latter, and that so inadequately that a detailed comparison with other groups of animals is not yet possible. Sufficient, however, is known to show that the development differs essentially from that of the Lampreys, thus rendering it all the more necessary that a fuller knowledge of it should be obtained.
The Cytoplasmic Inclusions of the Germ-Cells
Authors: Bronte Gatenby J. 
Published: April 2021

ABSTRACT
The posterior pole of the ovum of many Arthropoda, and especially of Holometabolous Hexapoda, has been shown to contain a cytoplasmic aggregation which ultimately becomes segregated into the germ-cells during early segmentation stages (4, 15, 21). On account of this the polar aggregation has been called the germ-cell determinant. In this paper I have made some attempt to ascertain the origin and composition of the germ-cell determinant, and I have also taken the opportunity to draw attention to the remarkable accessory or secondary nuclei.
Determination of Age in Honey-Bees.
Authors: Pixell-Goodrich Helen Li. M. 
Published: April 2021

ABSTRACT
It is of the utmost importance in the study of certain bee diseases to be able to separate definitely bees dying of a specific disease from those which are merely dying of old age. In the height of the honey-flow worker bees are said literally to work themselves to death in about six weeks after hatching. Consequently during the summer the normal daily mortality is very high—from a hive of fifty thousand workers being at least several hundreds. The last bees hatched out in autumn hibernate with the queen and thus attain an age of several months. It is popularly supposed and stated in some books on apiculture that an old bee may be recognised by her worn appearance, her body tending to be hairless and her wings frayed. The inaccuracy of this general statement and the uselessness of such a diagnosis for scientific purposes was soon apparent. I have carefully examined bees of many months in age (e.g. autumn bees flying in May) and compared them with those of a few weeks without finding any constant external differences. Conversely, relatively young bees may become hairless and their wings frayed under exceptional circumstances.
Protozoa parasitic in Termites
Authors: Cutler D. Ward 
Published: April 2021

ABSTRACT
In an earlier paper (1) I described the morphology and life-history of the commonest protozoa, Di trichomonas ter mit is, resident in the hind gut of an Indian termite, Archotermopsis wroughtoni, Desn. In the present paper I propose to consider in a similar manner other of these parasites, which have already been partially described by Imms (10) under the designation Species β. For reasons given pn page 399 I propose to found the new genus Jœnopsis, containing the two species J.cephalotricha and J. polytricha.
On the Bionomics and Development of Lygocerus testaceimanus, Kieffer, and Lygocerus cameroni, Kieffer (Proctotrypoidea-Ceraphronidae), parasites of Aphidius (Braconidae)
Authors: Haviland Maud D. 
Published: April 2021

ABSTRACT
1. Lygocerus testaccimanus, Kieff. is a hyperparasite of A p h i s saliceti, Kalt., through the primary parasite, Aphidius salicis, Hal. ; and L. earneroni, Kieff. is similarly a hyperparasite of Macrosiphum u r t i c a e, Kalt., through the primary parasite, Aphidius c r v i, Hal.
2. The Aphidius is attacked immediately before or after metamorphosis, when lying within the empty skin of the aphis within which it is reared.
3. The egg is laid, and post-embryonic development takes, place, outside the body of the host.
4. The evidence points to the conclusion that there are four larval instars and three moults.
5. The larvae differ in several particulars from those of the families of Proctotrypoidea previously described, and there is considerable difference in form between the early and later instars.
6. During development, which lasts about six days, the larva devours its host, and then pupates within the skin of the aphis for a further period of two weeks.
7. Two, and possibly more, broods are reared in the season ; and it is probable that the hyperparasite is a considerable check on the Asphidius in its control of plant-lice infestation.
8. Lygocerus, though occasionally attacked by its own species, was never found to be parasitised by another hymen-opteron. This immunity is probably due to the active movements with which the larva and pupa in the cocoon respond to external stimuli.
Observations on the Shape of the Nucleus and its Determination
Authors: Champy Christian , Carleton H. M. 
Published: April 2021

ABSTRACT
That the nucleus is extraordinarily variable in shape, not only in different animal cells but also in the same cell during the different phases of its ontogeny and metabolism, is a notorious fact. In the following notes, which embody a brief description of nuclear shape, we have also attempted to analyse, when possible, the factors responsible for this.
The Cytoplasmic Inclusions of the Germ-Cells: Part X. The Gametogenesis of Saccocirrus
Authors: Gatenby J. Brontë 
Published: April 2021

ABSTRACTIn this paper I have attempted to shed further light on that difficult problem, the oogenesis of an Annelid ; while Saccocirrus, as Goodrich has shown (26), is an Archi-annelid closely related to Protodrilus, it is probably much like other Annelida so far as its oogenesis is concerned.
Studies in Dedifferentiation. IV. Resorption and Differential Inhibition in Obelia and Campanularia
Authors: Huxley J.S. , de Beer G.R. 
Published: April 2021

ABSTRACT
Confirmation is given of the results of Loeb, Thacher, Godlewski and Gast, and others, in showing that the hydranths of hydroids (in this case Obelia and Campanularia) when exposed to unfavourable conditions proceed to dedifferentiate and to be resorbed, wholly or mainly, into the stem. Exposure to toxic agencies accelerates the process. Too great concentration of poison kills the zooids before dedifferentiation starts. Below the death-point, the acceleration is proportional to the concentration. The effect is non-specific, both KCN and HgCl2 producing the same result as prolonged exposure to laboratory conditions. When zooids are separated from the stem, resorption is impossible. Dedifferentiation, however, proceeds until an ovoid undifferentiated body packed with cells is produced. The tentacles are first affected, then the hypostome. In early stages, separate tentacles may fuse locally. Stumps of tentacles are, however, still present after the hypostome has quite disappeared. The body becomes ovoid, then spherical, and is finally reduced to a minute pigmented dot. The surface tension of the dedifferentiated zooid causes the emigrated zooid cells to flow into the stem. In later stages spontaneous pulsations of the stem and of the zooid (these possibly not spontaneous) occur. Dedifferentiation of the tissues of the tentacles starts at the tip. Progressive histological dedifferentiation of the endoderm cells can thus be clearly followed in a single section. Only after the mesoglaea at the base of the tentacle has ruptured can the contents be resorbed (confirming Thacher). Cnidoblasts with nematocysts can be distinguished within the gastrovascular cavity as resorption proceeds. They may also be seen phagocytosed within large cells, presumably immigrated endoderm cells. The dedifferentiation is regarded as due to interference with general metabolic processes, and especially with the production of the energy needed to maintain form against surfacetension. Resorption is regarded as the natural result of dedifferentiation when there are adjacent cavities into which the cells can migrate. In higher forms it has been largely replaced by phagocytosis.
Certain Phenomena of Tenthredinid Oogenesis as revealed mainly by Feulgen’s Nuclear-Reaction
Authors: Gresson R. A. R. 
Published: April 2021

ABSTRACTBy the use of Feulgen’s ‘nuclealreaktion’ certain points of Tenthredinid oogenesis have been subjected to closer study. The chromatin of the early nurse-cells of Allantus pallipes exists in the form of granules, the majority of which occur close to the nuclear membrane. In the older cells a nuclear network appears in which is distributed granules of chromatin. In Thrinax mixta, where the ovarioles were more highly developed, the chromatin of the nurse-cells occurs as granules scattered through the nucleus ; a nuclear network is not present, but certain granules appear to be connected by a thread. The granules which were shown to surround the nurse-cell nuclei (in material treated by Bensley’s method and also by fixation in Bouin’s picro-formol and subsequently stained in iron haematoxylin) and which were formerly regarded as chromatin emissions from the nurse-cell nuclei (9) were not revealed by Feulgen’s technique. They therefore cannot be regarded as chromatin. Their precise nature and origin remains undetermined. The nucleoli of the early nurse-cells of both species, as revealed by Mann’s methyl-blue eosin, are faintly basophil. Later they break up into a number of basophil bodies which undergo fragmentation ; formerly (technique and reference as in 1) the basophil nucleolus and the basophil bodies originating from it were termed ‘nuclear material’ undergoing fragmentation. While this basophil nucleolar material presents a fragmented appearance, it increases in amount as evidenced by the large number of basophil bodies present in the older nurse-cell nuclei. This material is utilized for the nourishment of the egg after the latter engulfs the nurse-cell nuclei. Nucleolar extrusions to the cytoplasm do not occur. The behaviour of the chromatin of the follicle-cell nuclei is similar to that of the nurse-cell nuclei except that in Allantus pallipes the nuclear chromatin network as demonstrated by Feulgen’s technique disappears in the older cells. The nucleoli of the follicle-cells are basophil. They become broken up in the older cells, but in most cases the resulting masses remain in contact. Nucleolar extrusions to the cytoplasm do not occur. The occurrence of deeply basophil material in the cytoplasm of the follicle-cells of Thrinax mixta stained with Mann’s methyl-blue eosin, formerly described for Bonin fixed material stained in iron haematoxylin (9), suggests that some substance in solution may be passed into the ooplasm ; extrusion of granules from the follicle-cells to the ooplasm does not take place. The absence or non-visibility of chromatin (Feulgen’s technique) from the oocytes of Thrinax mixta, and its disappearance from the older oocytes of Allantus pallipes, would indicate that the chromatin undergoes a chemical change during oogenesis such as suggested by Koch for Chilopods. The oxyphil and basophil nucleoli of the oocytes do not react to Feulgen’s technique for chromatin ; this agrees with Ludford’s findings for the mouse and forLimnaeastagnalis.
Notes on the Development of the Chondrocranium of Polypterus Senegalus
Authors: Moy-Thomas J. A. 
Published: April 2021

ABSTRACT
The chondrocranium of the existing specimens of the larval Polypterus have been redescribed, and the earlier specimens figured for the first time. The development of the following structures have not been described previously in Polypterus:
The lateral commissure which forms first from the prootic and then the post-palatine process. The taenia marginales, which arise as distinct cartilages. The development of the visceral arches and the temporary fusion of the first and second hypobranchials and ceratobranchials.
This development is then briefly compared with those of Scyllium, Amia, Lepidosteus, Acipenser, and Teleosts; a strong likeness being shown between it and that of Amia. The view of Goodrich is thus afforded additional support.
Notes on Odontosyllis
Authors: Goodrich Edwin S. 
Published: April 2021

ABSTRACT
During a recent visit to the Biological Station in Bermuda, my attention was drawn to the interesting ‘fire-worm’, Odontosyllis enopla Verrill, by Dr. E. L. Mark, who kindly helped me to obtain living specimens. The strange swarming habits of this Syllid have been described by Galloway and Welch (1916), who have also given a good general account of its anatomy. Certain points which escaped them, more especially concerning the structure of the alimentary canal and nephridia, seem to be worthy of special notice and are here described.