bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Bionomics and Post-Embryonic Development of certain Cynipid Hyperparasites of Aphides.
Authors: D. Haviland Maud 
Published: April 2021

ABSTRACT
Bothryoxysta curvata, Kieff., Charips victrix, Hartig, and Alloxysta erythrothorax, Westw., are hyperparasites of aphides through Aphidius (Braconidae). Reproduction may be either sexual or parthenogenetic. The egg is laid in the haemocoele of the host larva before the death of the aphid, and post-embryonic development is internal. A trophic membrane of hypertrophied cells is formed round the embryo. The larva is, at first, hypermetamorphic ; and exhibits greater development of the chitinous cuticle than is usual in endoparasites ; but in the succeeding stages it approximates more closely to the general hymenopterous type. G. The development of the Aphidius is arrested at a certain point, and metamorphosis does not take place. The Cynipid, when ready to pupate, makes its way out of the Aphidius, whose remains it devours, and undergoes metamorphosis within the cocoon previously woven by the latter in the skin of the aphid. These forms differ in certain particulars from the ento-mophagous Cynipidae previously described, and the chief differences are discussed. Comparison is also made of the larvae of other Hymenoptera Parasitica, particularly of Perilampus. Certain problems of metabolism are pointed out, and it is suggested that respiration may be partly rectal. These Cynipidae are economically injurious as they check the Aphidius in its destruction of plant-lice; but there is high mortality among the larvae owing to secondary parasitization of the Braconid by other hyperparasitos.
Notes on the Larval Skeleton of Spatangus purpureus.
Authors: Ohshima Hiroshi 
Published: April 2021

ABSTRACT
Although ‘one of the very first Echinoderms of which artificial fertilization and rearing of the larvae were undertaken’ (Mortensen, 6, p. 14), the development and especially the structure of the larval skeleton of Spatangus purpureus have been rather imperfectly known. Krohn’s descriptions and figures (2, 3) are not quite satisfactory with regard to the skeletal structure, and, moreover, the larvae described in his second paper are doubtful as to their specific identification (Mortensen, 6, p. 15). Through Mortens on’s renewed observations on the artificially-reared larvae of this species (6, pp. 14-17) the external features of the larval development are now made clearer. As to the larval skeleton, however, he was only able to give some brief information owing to the unfortunately bad state of preservation of his specimens. Among other Spatangoids, Echino - cardium cordatum and Brissopsis lyrifera were carefully studied by Maebride (4) and Mortensen (7, pp. 144-8), and the larvae of these three species have been shown to have such a striking resemblance to each other in early stages that it is desirable to ascertain some more minute diagnostic characters for each species. In such circumstances it seems not unnecessary to put on record detailed descriptions of the skeletal structure of the larva of Spatangas purpureus.
The Behaviour of the Golgi bodies during nuclear division, with special reference to Amitosis in Dytiscus marginalis.
Authors: Ludford Reginald James 
Published: April 2021

ABSTRACT
Dictyokinesis, or division of the Golgi bodies during cell division, has recently been worked out by Professor J. Bronte Gatenby and the present writer in the male germ-cells of several animals (5). It was found that the distribution of the Golgi elements, or dictyosomes, to both halves of a dividing cell was a very haphazard process and was unaccompanied by any splitting of the dictyosomes such as occurs in the case of the chromosomes. In the cricket Stenobothrus, the dictyosomes become scattered in the cytoplasm of the spermatogonium before cell division takes place, and they remain in this condition during meiosis, so that approximately a half become contained within each of the newly-formed cells. A different process, however, occurs in the Mammals, Mus and Cavia, and in the Molluscs, Helix and Limnaea. The Golgi bodies in the spermatogonia of these types consist of a number of dictyosomes arranged around the archoplasm, inside which is the centrosome. As this latter organ divides, preparatory to the formation of the spindle, its two constituent parts separate and carry with them to both ends of the cell, approximately half of the archoplasm, still with the dictyosomes attached. During late prophase, the dictyosomes become temporarily detached from the archoplasm and scattered throughout the cell, and then at the late telophase they collect together again around the archoplasm.
Histology of the Soft Parts of Astraeid Corals.
Authors: Matthai G. 
Published: April 2021

ABSTRACT
The following account of the histology of the soft parts of the Astraeidae is supplementary to the description given in the Introduction to my paper on ‘A Revision of the Recent Colonial Astraeidae possessing Distinct Corallites’ (25, pp. 1-32). It is based on the study of a large number of polyps belonging to various Astraeid species of the Indo-Pacific and Atlantic regions, particularly of Fa via fa vus (Forsk.), Fa via hululensis (Gard.), Coeloria daedalea (Ell. and Sol.), Leptoria gracilis (Dana), Eus mili a as per a (Dana). During a short stay at the Carnegie Marine Biological Station at Tortugas (July 16-August 2, 1915), living colonies of all coral species of that locality were kept under observation, but at that time larvae were extruded only from colonies of F avia f r a g u m (Esp.). These were fixed at different intervals during the free-swimming stage—from eight hours to about ten days—in Flemming’s fluid, corrosive acetic solution, and Bouin’s fluid, and were subsequently sectioned serially to thicknesses of 4 μ, 6 μ, 8 μ, and 10 μ in order to compare their histology with that of adult colonies. No larvae of any species were obtained during a subsequent visit to the Bermudas (Aug. 20 - Sept. 14). Solid embryos lying in the coelenteric cavities of polyps from a colony of F a via fragum, which Dr. Vaughan forwarded to Professor Gardiner from South Bight, Bahamas, and which have been sectioned, were also studied.
The Yolk-Sac and Allantoic Placenta in Perameles.1
Authors: Flynn T. Thomson 
Published: April 2021

ABSTRACT
It is proposed in the present communication to initiate the publication of a series of papers dealing with marsupial embryology. The facts and interpretations embodied will be based on result of an investigation into an amount of marsupial material now collected in the Biological Laboratory of the University of Tasmania and fairly representative of the Tasmanian fauna.
Nuclear Divisions in Amoeba proteus.
Authors: Taylor Monica 
Published: April 2021

ABSTRACT
No definite answer, so far as I have been able to ascertain, has yet been given to the question that is inevitably provoked by the spectacular rapidity with which amoebae increase in number in laboratory cultures, viz. ‘How does the nucleus divide ?’ In attempting to answer this question it is important to remember, a fact which five years’ experience in cultivating amoebae on a large scale has taught, that the most luxuriant cultures are subject to periods of depression. Unless the necessary precautions be taken (5) they die down and remain dormant for a varying period of time, then gradually recover.
The Transition of Peritoneal Epithelial Cells into Germ-Cells in Gallus Bankiva
Authors: Gatenby J. Brontë 
Published: April 2021

ABSTRACT
In a fowl (Gallus bankiva) which possessed some male characters (comb, wattles, and male pugnacity) the ovary contained an adenoma and was atrophic. Within this effete ovary the peritoneal epithelium had begun to elaborate new testicular tissue. Certain regions outside the gonad contained metamorphosing peritoneal epithelial cells. The transition of avian peritoneal cells into germ-cells takes place in a manner similar to what has already been described in Amphibia (Gatenby). The basophil peritoneal epithelial cell, at first clear, becomes granular. Its nucleus becomes spherical and a pure nucleolus appears: the cytoplasmic granules pass from basophility to oxyphility. At this period the cells divide and the oxyphil granules gradually dissolve into a smooth oxyphil ground cytoplasm. The cells, after division, are found to be arranged in columnar manner as spermatic tubules. In each tubule a lumen appears at a later period. Attention has been drawn to the work of Dr. Crew and Miss Fell, who have already described the metamorphosis of peritoneal cells into germ-cells.
On the Occurrence of the ‘Enteronephric’ Type of Nephridial System in Earthworms of the Genus Lampito
Authors: Bahl Karm Narayan 
Published: April 2021

ABSTRACT
The ‘enteronephric’ type of nephridial system previously discovered by the author in the genus Pheretima has now been shown to be present in the genus Lampito also. The present investigation extends the distribution of this new type of excretory system and makes it probable that it occurs in other genera as well. In essential the nephridial system of Lampito agrees with that of Pheretima previously described; but while in Pheretima the ‘enteronephric’ nephridia are minute and multiple and have been described as micronephridia, these nephridia in Lampito are large and paired in each segment and are described as meganephridia. There are three distinct kinds of nephridia in Lampito, namely the septal, the pharyngeal, and the integumentary; of these, the septal ones communicate with the lumen of the gut through an elaborate system of ducts, the pharyngeal tufts of nephridia open into the pharyngeal cavity through bundles of ductules, while the integumentarios open on the skin individually through separate nephridiopores. The septal nephridia of Lampito resembles those of Lumbricus in their shape and disposition, but in their place of opening they agree with the enteronephridia of Pheretima. Therefore both micronephridia (Pheretima) and meganephridia (Lampito) can be ‘enteronephric’. Since there is no anatomical difference between micro- and meganephridia but only a difference in size, this classification of nephridia should be abolished. A better system is to classify them according to their place of opening and recognize ‘exonephric’ and ‘enteronephric’ types of nephridia, and amongst each of these types to distinguish between those that have an open internal funnel and those in which the internal end is closed. The septal nephridia of Lampito are characterized by the presence of multiple funnels to a single nephridium, and since in some species all the funnels are functional and in others one is functional and the others vestigial, it is suggested that the branching of funnels is a stage leading later to the multiple nephridia of Pheretima. Close similarity in their nephridial and other systems suggests a genetic relationship between the two genera Lampito and Pheretima, and the suggestion is supported by facts of geographical distribution of the two genera. Lampito provides a connecting link between Megascolex and Pheretima.
The Cytological changes observable in irradiated Bean Root Tips
Authors: Patten Ruth E. P. , Wigoder Sylvia B. 
Published: April 2021

ABSTRACT
The effect of X-rays is divisible into two periods, one showing the immediate effect, the second period being one of recovery. The immediate effect includes gradual cessation of mitosis, and the production of abnormalities in those cells which were in the process of division or were about to divide at the time of irradiation. The length of time during which no cells enter into mitosis depends on the size of the dose. During the recovery period some cells again enter into mitosis but their division is usually of an abnormal type. Irradiation acts on cells in the interphase by interfering with some physiological process. These cells are then unable to enter into mitosis until the effect of irradiation has passed off.
On a new Hermaphrodite Syllid
Authors: Goodrich E. S. 
Published: April 2021

ABSTRACT
The worm described in this paper was found by me in material collected by the fishermen of the Zoological Station at Naples from the sandy bottom near the western shore of the bay of Naples. Although small it is fairly conspicuous, being milky white in colour and active in its movements. It belongs to the genus Pionosyllis, and like most of its near relatives bears its young attached in pairs on the segments of the middle region of its body, as admirably described and figured by Pierantoni (5). The breeding season begins in May, and the specimens I collected during my visit to Naples last April were not fully mature. To Mr. J. Z. Young, however, I am indebted for mature and embryo-bearing specimens collected in June.
On the skeleton of the hyoid arch in Rays and Skates
Authors: Beer G. R. de 
Published: April 2021

ABSTRACT
The relations to the afferent pseudobranchial artery of the lower ray-bearing part of the hyoid arch skeleton in Rays show that the latter is not the ceratohyal, but a pseudohyoid. Investigation of the development of Torpedo shows that the pseudohyoid arises distinct from the hyoid bar, and that the ceratohyal is much reduced. The ceratohyal in Rhynchobatus is not so much reduced as in Torpedo, Pristis, or Raja, and it still bears a small number of hyal rays. The pseudohyoid is formed as the result of fusion of hyal rays, and pseudohyoid bars are present more or less well developed in a large number of Sharks. The enlargement of the pseudohyoid and reduction of the ceratohyal in Rays is associated with the increased distance between the mouth and the first gill-slit, and the necessity for providing a support for the hyal rays and the anterior wall of the first gill-slit. Similar factors have been operative in the Dipnoi and have led to analogous results.
The Nephridia of Asymmetron and Branchiostoma Compared
Authors: Goodrich Edwin S. 
Published: April 2021

ABSTRACT
The excretory organs of Branchiostoma (= Amphioxus) are so peculiar, in that they resemble the protonephridia of many invertebrates and differ radically from the excretory tubules of other vertebrates (Goodrich, 1902 and 1909), that it is a matter of some importance to ascertain whether organs of similar structure occur in the allied genus Asymmetron. Andrews, so far as I am aware the only author who has dealt with this genus in detail, failed to find them in the Asymmetron lucayanum he described (Andrews, 1893, p. 229). During a recent visit to Bermuda I obtained specimens of this species,1 and give here the results of the study of fresh and preserved material carried out in the Bermuda Biological Station during last July and August and since in Oxford. A comparison is also made with the excretory organs of Amphioxus.
The Male Meiotic Phase in Five Species of Marsupials
Authors: Drummond F.H. 
Published: April 2021

ABSTRACT
This paper deals with the spermatogenesis of five species of marsupials including representatives of three families. The two species of Bettongia of the family Macropodidae have been studied in most detail. In the other forms little more has been done than to establish the number of chromosomes and the type of sex chromosomes.
On the Teeth of the Larval Belone vulgaris, and the Attachment of Teeth in Fishes
Authors: Moy-Thomas J. A. 
Published: April 2021

ABSTRACT
The upper jaw teeth of the larval Belone pierce the epidermis as solid structures, unattached to the bone and afterwards become attached by the growth of their bases directly to the premaxilla. These teeth are very similar in structure to those of the larval Eel. A curious feature is shown in their development, the original dentine cone becoming clear apparently to form enamel-like substance. The lower jaw and pharyngeal teeth of the larval Belone develop as hollow cones of dentine, and become attached to the bone either directly or by means of separate ‘intermediate ‘pediments of bone. All the teeth of Salmo, Amia, Acipenser, and Polypterus are attached to the bone directly or to upgrowths more or less continuous with the bones. The bony ‘intermediate’ plates of the Dipnoi fuse to form the adult tooth-plate, the actual denticles disappearing. The supporting pediments are shown to be only bony supports developed precociously in connexion with the teeth, and may be formed directly from the bone or separately as ‘intermediate’ pediments, and are in no way different from the remainder of the bone. The embryology of teeth and bone in fishes suggests that they are distinct structures, and that their close association in ontogeny and phylogeny is due to the necessity of acquiring a firm base, and not because they are parts of the same structure.
On the Significance of the Enteronephric Nephridial System found in Indian Earthworms: I. Evidence from their Habits and Castings
Authors: Bahl Karm Narayan 
Published: April 2021

ABSTRACT
In 1919 (1) I described in the pages of this journal a new type of nephridial system found in Indian earthworms of the genus Pheretima. The nephridia in this system are remarkable in that they discharge their excretion into the intestine instead of on to the surface of the body. The excretion is conveyed through a system of ducts, of which the most important are a pair of longitudinal excretory ducts lying above the intestine, one on each side of the mid-dorsal line; these ducts open into the intestine all along its length through segmentally arranged apertures. I gave the name ‘enteronephric’ to this new type of nephridial system to distinguish it from the ‘exonephric’ type found in Lumbricus, and put forward the suggestion, originally made to me by Dr. W. N. F. Woodland, that ‘the discharge of excretory fluid into the intestine may be a special adaptation for the conservation of moisture in a dry climate’. It was assumed that the water-content of the excretory fluid discharged into the gut was reabsorbed by the intestinal epithelium for the needs of the organism, while the solid excretory matters passed out of the body through the anus. Later, in 1924 (2), I found a similar ‘enteronephric’ system in another genus of Indian earthworms, Lampito (Megascolex), in which the nephridia are large and paired—meganephridia—like those of Lumbricus as contrasted with the numerous small micronephridia of Pheretima; but in the manner of their opening into the intestine through a pair of longitudinal excretory ducts and segmentally arranged apertures, these nephridia of Lampito agree with those of Pheretima. Still later in 1926 (3), I found that a third genus of earthworms called Woodwardiella also possessed an ‘enteronephric’ system very similar to what I had previously described in Pheretima and Lampito. I concluded, therefore, that this enteronephric type of nephridial system was widely prevalent amongst earthworms—particularly in the family Megascolecinae to which all the three genera possessing this type of nephridial system belong.
The Formation of the Hen’s Egg V. Histochemistry of Yolk-Formation Proteins1
Authors: Marza V. D. 
Published: April 2021

ABSTRACT
The best known protein in the yolk of the hen’s egg is vitellin. Next to that one finds livetin, Gross’s protein,1 and the nucleoproteins. According to Hugounencq and Morel there is 1μ40 gr. of vitellin in the hen’s egg. Livetin is in lesser quantity. The quantity of nucleoproteins does not go beyond 2 mgr.
On the Primitive Streak and associated structures in the Marsupial Bettongia cuniculus
Authors: Kerr T. 
Published: April 2021

ABSTRACT
A series of ten blastocysts of Bettongia cuniculus is described, covering a range of development from the appearance of the primitive streak to the establishment of the medullary plate. In the first blastocyst there has appeared a small area of ectodermal thickening between the centre of the embryonal area and its periphery, and it is suggested that this is the primordium of the primitive streak. In the second blastocyst a very young streak is present which does not reach either to the middle or to the periphery of the area, and whose centre is in nearly the same position as that of the first blastocyst. At its maximum the streak stretches about two-thirds of the way across the embryonal area. A groove develops down its middle and active mesoderm production occurs from its edges. The mesoderm forms an approximately oval area round the streak, and extends into an extra-embryonal position first posteriorly and then laterally. At the anterior end of the streak appears a broader, thicker region of similar but looser tissue, the primitive knot; from here grows forward the head-process in the usual way, and at the same time the endoderm underlying these two structures fuses with them. No lumen is present in the head-process at any stage. The originally circular embryonal area elongates until it becomes somewhat pear-shaped, and later it constricts in the middle. The thickened ring of endoderm at the edge of the embryonal area, the annular zone of proliferation of Hubrecht, is distinguishable at the time of appearance of the primitive streak; but the second thickened area, the prochordal plate, does not appear until the streak is well established, and except in its earliest stages is hard to delimit owing to its relative thinness and to the closely investing mesoderm which soon covers it. The question of mesoderm production from these sources is discussed, and it is concluded that while such does in fact occur in this form it is quite insignificant in amount as compared with that produced from the sides of the primitive streak. In the last stage described the medullary plate and chorda are well established, and the importance of the primitive streak is diminishing. Mesoderm, whose production now appears to be occurring chiefly by division of pre-existing mesoderm cells, is very much more abundant, and can be divided into three parts: thick sheets extending from near the axial line to beyond the edge of the medullary plate, condensations in which the pleuro-pericardial coelom is appearing anteriorly, and vascular mesoderm in which blood-vessels are forming. Blood-islands are not present within the vessels, and apparently are represented by groups of cells between the vessels. A well-formed prochordal plate is also present.