bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Observations on the Early Development of Didelphys Aurita. (Contributions to the Embryology of the Marsupialia.—V.)
Authors: Hill J. P.
Published: April 2021

The observations recorded in this paper are the outcome of the examination of a small amount of early material of (abstract) Didelphys aurita collected by the Percy Sladen Expedition in Brazil in 1913. The chief object of that expedition was the collection of embryological material of South American mammals, and more especially of the Didelphyidæ. Up to the beginning of 1916, our knowledge of the early development of the latter rested on the well-known account given by the late Emil Selenka in 1886 of that of the Virginian opossum (Didelphys virginian a). Selenka’s conclusions, as I have pointed out in my paper on the early development of Dasyurus (‘10), were derived from the study of a relatively small amount of material, much of it of very doubtful value, and differ in essential respects from my own, based on the study of an abundant material of Dasyurus, and as we should not expect à priori to find fundamental differences in the early development of two animals so closely related as Didelphys and Dasyurus undoubtedly are, the need for a re-investigation of the early development of the former was sufficiently obvious.
A Revision of Certain Points in the Early Development of Peripatus capensis.
Authors: H. Glen Edith
Published: April 2021

Some valuable material of Peripatus capensis and Peripatus Balfouri was very kindly presented to the Zoological Laboratory of the Imperial College of Science by the widow of the late Prof. Adam Sedgwick, and at the suggestion of Prof. MacBride, who handed over the material to me, I have revised two points in Prof. Sedgwick’s “Monograph of the Development of Peripatus capensis,” which had raised a great deal of controversy when the paper was published.
The Somatic Mitosis of Stegomyia fasciata
Authors: Carter Lucy A.
Published: April 2021

The diploid number of chromosomes in Stegomyia fasciata is four. A varying degree of parasyndesis (pairing of the chromosomes) is exhibited in the somatic cells, extreme parasyndesis giving a haploid count. Bach telophasic mass of chromatin gives rise directly to a synizetic nucleus instead of the usual “resting” nucleus. The nuclear membrane persists throughout mitosis. The homologous chromosomes pair either in anaphase or in telophase.
On the Cytomorphosis of the Enamel Organ in the Hake
Authors: Carter J. Thornton
Published: April 2021

In the Gadidæ each tooth is surmounted by a pointed cap of enamel which rests on a platform of dentine, whose central area extends into the enamel cap, thus affording a firm support without increasing the outside dimensions of the tooth over this area. The development of this enamel cap is associated with certain marked changes in the enamel cells investing it.
On the Orientation of Minute Objects for the Microtome
Authors: Newth H. G.
Published: April 2021

For some time past the work I have been engaged upon lias necessitated the sectioning of large numbers of minute larvæ, whose small size and lack of obvious symmetry or external “landmarks “made them extraordinarily difficult things to prepare for the microtome, and in no degree amenable to the ordinary methods of embedding. None of the various devices that are current will give, in my experience, anything approaching exact orientation—upon which often depends the very possibility of interpreting the sections when they are cut; and this is because in none of them are the essential operations conducted at leisure, at the ordinary temperature, and with the object plainly seen under the microscope. A method which combines the satisfaction of these requirements with the advantages of double-embedding in collodion and wax is given below. By its use I have been able to obtain precise orientation of such small objects as the early larval stages of Amphioxus, Ciona and Cucumaria,.and of the cleavage stages of Echinus and Ascidiella.
The Effects of Ions upon Ciliary Movement
Authors: Gray J.
Published: April 2021

The experiments described in this paper constitute an attempt to determine the necessary external conditions which support ciliary action. Concerning the mechanism of the cell itself practically nothing is known, and comparatively little work has been done to determine the factors involved by the external medium. In 1902-1906 R,. S. Lillie published a series of papers dealing with ciliary action; since then our knowledge of the physical chemistry of solutions of electrolytes has greatly increased, and it seemed desirable to re-open this line of investigation.
Some Observations on Caudal Autotomy and Regeneration in the Gecko (Hemidactylus flaviviridis, Rüppel), with Notes on the Tails of Sphenodon and Pygopus.
Authors: Woodland W. N. F.
Published: April 2021

During the rainy seasons (July to October) of 1914 and 1918 I made a large number of observations and experiments on the facts of caudal autotomy and regeneration in the common Indian Gecko, Hemidactylus flaviviridis1 (Rüppel), a very familiar and useful ‘snapper-up of unconsidered [insect] trifles ‘found on the walls of every bungalow in the United Provinces. In January 1915 I read a brief paper2 on the subject at Madras on the occasion of the second meeting of the Indian Science Congress, but until the present year I have not had an opportunity of writing up a complete description of the results obtained by me.
The Occurrence of Situs inversus among artificially-reared Echinoid Larvae
Authors: Ohshima Hiroshi
Published: April 2021

A Remarkable case, where a hydrocoele and its associated structure had developed only on the right side instead of on the left side of the body, as in normal specimens, came under my notice among the artificially reared larvae of Echinus m i 1 i a r i s.
A Critical Study of the Facts of Artificial Fertilization and Normal Fertilization
Authors: Gray J.
Published: April 2021

Facts concerning the process of fertilization and of artificial parthenogenesis have steadily accumulated during the past thirty years, and although numerous suggestions have been put forward as partial explanations of this imposing mass of experimental evidence, yet there are only two theories which claim to give an adequate picture of even a majority of the known facts. These theories we owe to J. Loeb (24) and to F. R. Lillie (20). According to Loeb, the activation of an unfertilized egg is effected by the introduction into the egg of two substances, (i) a specific cytolysin, which brings about the destruction of the surface layer of the egg, and (ii) a substance which limits or controls the destructive influence of the cytolysin. On the other hand, Lillie holds that the union of the egg and spermatozoon is only possible in the presence of a specific substance or fertilizin which is secreted by the unfertilized egg ; if all three elements are present fertilization and normal development take place.
The Nature of certain Ovum-like Bodies found in the Seminiferous Tubules
Authors: Crew F. A. E. , Fell Honor B.
Published: April 2021

During the systematic examination of a goat with, an abnormal reproductive system sent to this Department by Mr. T. H. Gillespie, Director-Secretary of the Scottish Zoological Park, certain peculiar ovum-like bodies were found within the seminiferous tubules of the ectopic testes.1 In order to decide as to the exact nature of these, it was necessary to extend the investigation so as to include an examination of other abnormal gonads. To Mr. M. S. Pease, of the School of Agriculture, Cambridge, we are indebted for an undescended testis from a rabbit in which he had found bodies exactly similar to those found by us in the case of the goat, and also for permission to include a description of his series in this paper. An undescended testis from the human was sent to this Department by Sir Edward Sharpey Schafer, and one from a cat by Mr. A. Cameron, of the Royal (Dick) Veterinary College. Without this material our work must have remained very incomplete, and in acknowledging our debt we wish to render our grateful thanks.
Glossobalanus marginatus, a new species of Enteropneusta from the North Sea
Authors: Meek Alexander
Published: April 2021

The only species of Enteropneusta which have been recorded from the area of the British Isles are two species of the genus Dolichoglossus, one from the west coast of Ireland (Ballynakill Harbour—Tattersail, 1905), the other from the west coast of Scotland (Sound of Mull—Assheton, 1908). These presumably, like other species of the genus, have an embryonic development. The occasional capture of Tornaria off the coast of Ireland, in the Irish Sea, in the Channel, and at St. Andrews have indicated that Balano-glossus and its allies occur also in the area, but hitherto such have evaded capture. The specimen about to be described was captured off the Fame Islands and thus extends the range of the group to the east coast and the North Sea, and it has the further importance of belonging to a genus and a family the members of which more than probably pass through a larval phase. The specimen was obtained during a survey made off the coast of Northumberland by the Ministry of Agriculture and Fisheries at a depth of about 52 fathoms off the Longstone, the instrument in use being a small Petersen grab. The position of the boat at the time (9 a.m. on August 22, 1921) was 55° 83′ N., 1° W. I have to thank the scientific staff for kindly submitting the specimen to me for description.
On the Biology and Structure of the Larvae of Hydrophilus caraboides L
Authors: Pavlovsky E. N.
Published: April 2021

In May 1918 I captured in the vicinity of Petrograd some cocoons of a hydrophilus beetle, one of which I kept for breeding purposes. On June 13 there emerged about fifty small larvae very similar to Hydrophilus caraboides. These latter are characterized by the presence of a pair of lateral (pleural) appendages covered with a dense brush of hairs on each of the seven abdominal segments (Text-fig. 13, pla).
On some remarkable new Forms of Caryophyl-laeidae from the Anglo-Egyptian Sudan, and a Revision of the Families of the Cestodaria
Authors: Woodland W.N.F.
Published: April 2021

Four remarkable new species of Caryophyllaeidae from the Anglo-Egyptian Sudan are described, three of which (from Siluroid fishes) are referred to a new genus, Wenyonia —W. virilis, W. acuminata, and W. minuta—and the fourth (from M o r m y r u s c a s c h i v e) to the original genus Caryophyllaeus—C, filiformis. The chief characteristics of the new genus are the situation of the sexual apertures in the anterior half of the body, and the elongated uterus. The family Caryophyllaeidae, after deletion of the genera Diporus, Monobothrium, and Glaridacris, thus contains three genera—Caryophyllaeus, Archigetes, and W e n y o n i a—all of which are re-defined, with their known species. Very young immature forms of Wenyonia occur in the same (Siluroid) host as the adult and are devoid of a ‘caudal ‘appendage, whence it would appear that the life-history of these new forms is different from that of C. laticeps. The three families of the Cestodaria—Caryophyllaeidae, Gyrocotylidae, and Amphilinidae—are re-defined. The Cestodaria, after eliminating Bangui ni cola (a Trematode ?), are provisionally grouped into two Orders : the Amphilinidea (with one family, the Amphilinidae) and the Paralinidea (with two families, the Caryophyllaeidae and the Gyrocotylidae), the latter being closely allied to the Bothriocephalidae. These two Orders are defined.
The Cleavage of the Egg of Lepidosiren paradoxa.
Authors: E. Miller Agnes
Published: April 2021

The process of cleavage in Lepidosiren was first described by Professor Graham Kerr in his paper on the development of the external features of this animal in the ‘Philosophical Transactions of the Royal Society B, vol. cxcii, 1900. Since the date of Professor Kerr’s expedition additional material has become available from which it has been possible to make up a more completely graduated series of segmentation stages. The following paper deals with this material and may be regarded as supplementing Professor Kerr’s paper. In referring to the various stages I use the same numbers as Professor Kerr used in the paper already mentioned and also in his ‘Normentafel’.1
The Genital Organs of Stylaria lacustris, with an account of their Development
Authors: Mehra H. R.
Published: April 2021

1. The genital organs of Stylaria lacustris are described in detail. The vas deferens opens into the atrium on the anterior face near the opening of the ejaculatory duct and not at the top as described by all the previous authors. The prostate surrounds not only the atrium but also the vas deferens in segment 6.

2. The prostate secretion passes through the atrial epithelium, which consequently hypertrophies and disappears.

3. The development of the genital organs proceeds with great rapidity when the sexual phase appears, which occurs only once a year from the end of September to the beginning of December. There is no long intervening period between the development of the gonads and other genital organs.

4. The order of development seems to be connected with the time or order of their functioning.

5. The gonads are peritoneal in origin. The sperm-sac and ovisac are large portions of the body-cavity enclosed by the extension backwards of septa and respectively.

The yolk-mass is formed by a process of metabolic change in the cytoplasm of some of the ova.

6. The sperm-duct is partly peritoneal in origin and partly an ectodermal invagination. The funnel and the vas deferens rudiments arise by a proliferation of the peritoneal cells on the anterior face of septum , which assumes the form of a deeply staining plate of columnar cells with prominent nuclei. This after the funnel rudiment becomes the sperm-cord and penetrates the septum in front of the ovary, reaching near the body-wall the atrial rudiment, which is soon formed as an ectodermal invagination.

The prostate cells arise from the peritoneum near the ventral body-wall of the sixth segment in the neighbourhood of the atrial rudiment.

7. The rudimentary female funnel, which opens out at the female opening, arises as an outgrowth from the peritoneum at the base of septum .

8. The spermatheca arises as an invagination from the ectoderm. I agree with Bergh that the spermathecae are to be considered as new structures, and not phylogenetically connected with the genital ducts as Gatenby supposes to be the case in Tubifex rivulorum.

9. A few stages obtained showing the development of these organsin Nais elinguis confirm the above observations.
Notes on four Astomatous Ciliates from Oligochaete Worms
Authors: Mackinnon Doris L. , Adam D. Ines
Published: April 2021

If a really satisfactory classification of the astomatous ciliates is ever to be made, it is necessary that many more of the earliest recorded forms should be re-investigated and re-described. This is the object of our present work, and is the excuse for the notes that follow.
On an Ovum of Ornithorhynchus exhibiting Polar Bodies and Polyspermy
Authors: Gatenby J. Brontë , Hill J. P.
Published: April 2021

Amongst the Monotreme material in the possession of one of us are two large slides of sections of a uterine egg of Ornithorhynchus labelled c, diameter 6·75 mm. (No. 1, August 19, 1901). This particular egg was cut on the sliding microtome, after embedding in Stepanow’s clove-oil celloidin, at the time Wilson and Hill were working up the material for their paper on the development of Ornithorhynchus (1) in the hope that it would exhibit an early phase of cleavage. In this respect the egg proved a disappointment, being unsegmented, and it was put on one side, though it was noted at the time that it was possibly at the stage of polar body formation. We have recently had occasion to re-examine the sections, and though we have had considerable difficulty in interpreting the structural appearances in the region of the germinal disc and have been unable to distinguish either the male and female pronuclei or the cleavage nucleus, we think that the egg is actually at the stage just following the formation of the polar bodies. It is therefore unique and worthy of a brief description. Moreover, the sections, considering the refractory nature of the material, are quite good, the sectional plane coinciding almost perfectly with the vertical or polar axis, and afford a very clear picture of the general structure of the egg and morespecially of the latebra and its relations to the germinal disc, of which no detailed account exists.
On Two Tubes of Polyodontes, and on the Discharge of the Ova in Thelepus
Authors: McIntosh W. C.
Published: April 2021

In the ‘Annals of Natural History ‘1 1894, some observations were made on the various tubes formed by marine annelids, the structure of many being interesting both in regard to the finished masonry of the tube, its branches at the anterior end, its processes along the surface,, but no tube of Polyodontes had then come under observation or been sufficiently described by any author. In the earlier accounts of Polyodontes little reference was made to the tube, De Quatrefages,2 for instance, mentioning that Polyodontes (Acoetes) Pleei inhabits a tube—analogous to that of many other errant and sedentary annelids—composed of a flexible substance, coriaceous, and resembling wet leather, a description which needs considerable amplification in the case of the remarkable tubes to be alluded to subsequently. In the fine monograph of Eisig,3 again, no reference is made to the tube of Polyodontes, though its secretory apparatus is ably dealt with.
Studies on the Organization and Development of Scorpions
Authors: Pavlovsky E. N.
Published: April 2021

In this work I have undertaken the study of the different organs of scorpions from the point of view of comparative anatomy. The extensive literature on this subject contains a number of gaps (e. g. the male genital organs have not been investigated in sections), and besides in the majority of works the material is restricted to some species of the genera Buthus or Euscorpius. The necessity of studying the organization of the tropical forms has, however, been felt for a long time. In the present investigations I had two aims in view. In the first place I undertook the re-examination of the structure of some of the most interesting organs of certain representatives of the families Buthidae, Chactidae, and Scorpionidae, on fresh material collected in most cases by myself in Algeria and Tunis (Scorpio maurus, Buthus australis). The collection of material (Buthidae : Buthus caucasiens, Anomalobuthus rickmersi, Liobuthus Kessleri) was continued by me in the summer of 1915 in Russian Turkestan.
Note on Placodes and the Ophthalmic Nerves
Authors: de Beer G. R.
Published: April 2021

As a result of the recent advance in neurology, various facts relating to the development of cranial nerves have come to acquire additional significance in connexion with function. It has been known for a considerable time that the dorsal roots of the cranial nerves have more than one method of origin. First, there is of course the neural crest, the cells of which give rise to the ganglia of the dorsal roots of the spinal as well as of the cranial nerves. In the Anamnia, in addition, some elements of which the cranial dorsal nerves are composed are derived from two series of ectodermal placodes. The more dorsal of these is the dorso-lateral, the more ventral the epi-branchial series of placodes. These placodes are regions of thickened ectoderm, cells of which proliferate inwards towards the underlying ganglia.
Amoeba proteus: Some new Observations on its Nucleus, Life-history, and Culture
Authors: Taylor Monica
Published: April 2021

When reading over the manuscript of ‘Nuclear Divisions in Amoeba proteus’ (14), a kind office for which, on this casion, I am once more indebted to him, Professor Graham Kerr expressed a wish that I should undertake a more detailed study of the behaviour, during division, of the chromatin blocks described in that paper. At the same time I became interested in a series of publications by Drs. Atkins and Lebour in connexion with hydrogen-ion concentration, two of which (1 and 2), particularly, seemed to open up a useful line for me. Having a large number of pedigree Amoeba cultures, with field-notes of their history extending back to 1916-17, as well as cultures of other micro-organisms, there was plenty of scope for testing the value of this physico-chemical factor in the cultivation of micro-organisms under laboratory conditions. I should like to take this opportunity of thanking the authors for their courteous response to my many inquiries, Dr. Atkins having given me the benefit of his expert advice in matters of a physico-chemical character.
The Development of the Male Genitalia of Homoptera, with Preliminary Remarks on the Nature of these Organs in other Insects
Authors: Singh-Pruthi Hem
Published: April 2021

While there exist extensive memoirs on the comparative anatomy of the male genitalia of several insect orders, works dealing with their ontogenetic development are very few, with the consequence that up to now there is practically no unanimous agreement as to the fundamental or basic plan of these organs in the insect kingdom. Zander (119, 120, and 121), in a series of short papers, described the post-embryonic history of the external genital appendages of Hymenoptera, Trichoptera, and Lepidoptera, and came to the conclusion that the ‘penis’ an unpaired median organ in the adult, originates in the young as a pair of appendages which sub sequently fuse with each other along the median line and develop into the single tubular organ found in the imago. Zander, however, did not attempt the homologies of the various genital appendages, and, moreover, as will be shown later, his account of the mode of origin of the above-mentioned pair of appendages is also open to question. Previous to Zander, Verson and Bisson (108) in the case of Bombyx mori, and Michaelis (73) in that of the honey bee, had also shown the origin of the penis from a pair of appendages. Verhoeff (106), Esch erich (34 and 35), &c. pointed out the paired-appendage nature of the penis even in the adult condition in some Thysanura. Christophers (23) and Christophers and Cragg (24) studied the development of the genitalia in Diptera and Cimex (Rhynchota-Heteroptera) respectively, and confirmed the main conclusions of Zander. The account of Cimex alone cannot be said to be representative of the whole order Rhynchota, as this form, apart from being highly specialized, is devoid of—as are all other Heteroptera—the subgenital plates (see below), whose nature is of immense morphological importance, and is still sub judice. Besides, my observations on Idiocerus, belonging to the allied sub-order Homoptera, while in accord with Christophers and Gragg’s findings with regard to the mode of origin of the penis, lend little support to most of their conclusions, and in some points, e. g. history and nature of the associated internal ducts, are at variance with their results.
On the Structure and Development of the Enamel in Mammals
Authors: Jasswoin G.
Published: April 2021

According to the views of some investigators (v. Ebner 1902, Smrecker 1905, Eklöf 1915, Studnicka 1917, and others) between the enamel prisms there is a substance differing from the latter and known as the cementing substance (‘Kittsubstanz’). Other investigators (Waldeyer 1869, Walkhoff 1903, and others), however, assert that this cementing substance represents nothing else but the cortical layers of prisms which have fused together and, consequently, are immediately adjacent to each other.
Seasonal and Sexual Variation in the Thyroid Glands of Cats
Authors: Lowe Esther
Published: April 2021

An account of the variation in the histological condition of the thyroid gland of the sheep, with regard to age, sex, and season, has already been published (Lowe, 1930). The results embodied in the present paper formed part of the same investigation.
Microchemical Tests for Fats, Lipoids, and Vacuoles with special reference to Oogenesis
Authors: Nath Vishwa
Published: April 2021

It is generally believed by cytologists that fats blacken quickly in osmic acid, whereas lipoids take a much longer time. This view seems to be erroneous, as the time required by osmic acid to blacken a particular sample of fat or lipoid depends entirely on its degree of unsaturation and its previous state of oxidation. Films of a sample of completely hydrogenized fat, with iodine value nil, failed to blacken in osmic acid, even in seven days at 40° 0. Samples of fat, therefore, must exist which actually take longer time to blacken in osmic acid than some highly unsaturated lipoids. It follows, therefore, that a granule in the cell, which goes black in osmic acid in a short period, cannot be identified as true fat unless it also stains intensely in Sudan III and Scharlach R. These fat tests have been employed on eggs of animals representing many groups. In Pheretima, Culex, Dysdercus, Crosso- priza, Plexippus, and the rabbit, the Golgi material can be blackened in short periods of osmication, but it cannot be stained even slightly with Sudan III and Scharlach R during any stage in oogenesis. It must, therefore, be interpreted not as fat but as very highly unsaturated or very little oxidized lipoid. In earlier stages of the oogenesis of Ophiocephalus Rana, Emyda, Gallus, Lucióla, Periplaneta, P al a emo n, and Paratelphusa, the Golgi material does not stain at all with Sudan III and Scharlach R, even though it can be blackened in short periods of osmication. It must again be interpreted, not as fat, but as highly unsaturated or very little oxidized lipoid. At a certain stage in oogenesis these lipoids are converted into fats when they stain brilliantly with Scharlach R and Sudan III. In Rita the Golgi material of early oocytes consists of very nearly fully saturated lipoid, as it does not go black in short periods of osmication, and takes thirty-two days to impregnate in Mann-Kopsch. It does not stain with Sudan III and Scharlach R, but by the time the egg measures 1 mm. it is converted into fat and begins to stain intensely with these dyes. A chart is published recording the reactions of fats, lipoids, and vacuoles to various microchemical tests.
Improved Technique for Non-aseptic Tissue Culture of Helix aspersa, with Notes on Molluscan Cytology
Authors: Brontë Gatenby J. , Hill Joyce C.
Published: April 2021

By keeping pieces of mantle cavity wall in Hédon Fleig saline it is possible to make cultures which grow out for about five days. After that time the bacteria have increased so enormously that growth is checked, though the cultures will live for several weeks longer in a suspended condition. The main type of cell which grows out is an amoeboid element, identical, it is believed, with the general connective elements of the normal tissue of the snail. Neutral red stains, is segregated, or is deposited in the various categories of cells, in various ways. For example, in spermatocytes it appears almost always inside the Golgi apparatus, thus forming with the dictyosomes a ‘zone de Golgi’ of Parat. In the pulmonary epithelial cells the neutral red at once stains the pre-formed granules which are visible in unstained living cells. These granules are not directly related to the Golgi bodies. In amoebocytes the neutral red appears principally as large segregated globules, anywhere in the cytoplasm. Finally, into the mantle epithelial cells it is difficult to get neutral red, when other cells are already well stained. The only homologous bodies in the cytoplasm of these various categories of cells are the Golgi bodies and mitochondria. In no case has a mitotic figure been found in any Helix culture. Cells suggesting division by amitosis are commonest when the cultures are growing out fastest.
La Spermatogenèse et l’Ovogenèse du Mallophage Goniodes stylifer
Authors: Perrot J. L.
Published: April 2021

Doncaster et Cannon, dans leur travail sur la spermatogenèse de Pediculus human us, sans arriver à des conclusions précises, posèrent un problème du plus haut intérêt concernant le cycle chromosomique du Poux.
Studies on the Cytology of the Harderian Gland of the Rat
Authors: Duthie E. S.
Published: April 2021

In a recent study by the author (1933 a, b) of the secretory process in various gland-cells, it was shown that (a) the secretory granules originated at the base of the cell in relation to the mitochondria, and later moved into the Golgi zone where maturation occurred, and (b) that development of the granules occurred in every case in intra-cellular vacuoles, these vacuoles being also the spaces inside which the vital dyes, Janus green and neutral red, are segregated. The present short study was undertaken, since it was noted that secretion formation in the Harderian gland-cell is different from that of gland-cells included in the former studies, and that in consequence certain points raised in the former work were in this case more clearly demonstrated. The purpose of the paper is then a description of the cytological elements of the gland-cell secretory granules, mitochondria, and Golgi apparatus, and a comparison of these structures with those obtained by vital staining with neutral red and Janus green.
The Golgi Apparatus in the Thyroid Gland of Amphibians, in its relation to Excretion Polarity
Authors: Uhlenhuth Eduard
Published: April 2021

In 1923 Nassonov reported observations which suggested that the Golgi apparatus is concerned in the elaboration of the secretion droplets of gland-cells; he therefore concluded that the Golgi apparatus is the secretory organ of the cell.
The Early Development of the Nemertean Cephalothrix rufifrons
Authors: Smith J. E.
Published: April 2021

The following account is based on material collected at Ply-mouth. Most of the embryonic and larval stages were obtained in the Spring and Summer of 1932 during which time I was holding the Student Probationership at the Marine Biological Laboratory. In April 1933 I was able to add most of the missing developmental stages.
Development of the Female Genital Ducts in Trichoptera
Authors: Dodson M. E.
Published: April 2021

The object of this investigation is to determine the structure of the female genital ducts, their accessory structures and development in the Trichoptera, and to make a comparison with the structure and development of the female genitalia in Lepidoptera as at present known. The development of the organs in the latter group has been worked out by Jackson on Vanessa io, which, in spite of being a fairly advanced type, bears certain important resemblances to the Trichoptera.
The Autonomic (Enteric) Nervous System of Amphioxus Lanceolatus
Authors: Boeke Prof. Dr. J.
Published: April 2021

The present paper contains in a more detailed and better illustrated form the same facts as were described in a short communication in the ‘Proceedings of the Royal Academy of Science of Amsterdam’ of the year 1933 (vol. xxxvi, No. 10, December 1933).
The Revision, Systematic Position, and. Origin of Diplodinium (Polyplastron) multi-vesiculatum and Diplodinium (Polyplastron) bubali
Authors: Wertheim P.
Published: April 2021

Diplodinium (sub-genus Polyplastron) multivesi-culatum (Dogiel and Fedorowa, 1925) undoubtedly is one of the most interesting representatives of the Infusorian family Ophryoscolecidae (which occurs in the stomachs of ruminants), especially from the systematic and phylogenetic standpoint. The origin of this species shows some peculiar causes which are operative in the development of these Infusorian species, but besides that the present treatise points out some new aspects regarding the development of new species in general.
Observations on the Effect of the Ultra-centrifuge on some Free-living Flagellates
Authors: Patten Ruth , Beams Harold W.
Published: April 2021

When the three species of free-living flagellates employed in this investigation are subjected to the high centrifugal force obtained by the use of the air-driven centrifuge, stratification of the cytoplasmic components and inclusions takes place. This stratification is most noticeable in the chlorophyll-bearing Euglena. The chloroplasts form a belt having on the centrifugal side paramylum and neutral-red bodies, while the clear cytoplasm containing small spherical bodies, probably mitochondria, is at the centripetal pole. This stratification is a temporary process. Complete redistribution of the parts can take place. The orientation of the stratification is not dependent on the morphological polarity of the organism. The heaviest components may occupy the anterior, posterior, or lateral part of the organism. There is no evidence that the bodies which stain intravitally with neutral red are homologous with the Golgi bodies of the metazoa. On the contrary there is some new evidence to support the findings of Baker (1933) that these bodies stainable with neutral red give a metachromatic reaction with Meyer’s methylene-blue method, and are therefore probably identical with volutin. We have reached no satisfactory conclusion regarding what structures represent the Golgi apparatus. The theories put forward by other observers are briefly discussed. Fixatives containing osmic acid show spherical bodies close to the periphery of the organism. They are not moved by the centrifugal force. Short notes are given on the effect of the ultra-centrifuge on Menoidium sp. and on Chilomonas paramecium. As in Euglena the heaviest materials in Menoidium are the paramylum and bodies stainable with neutral red. In Chilomonas starch grains and neutral-red-stainable bodies are displaced to the centrifugal pole. In control specimens of Menoidium there is sometimes a natural stratification to be observed —the paramylum and neutral-red bodies being gathered together usually at the anterior end of the organism.
A Study of the Histology of the Pituitary Gland of the Skate
Authors: Howes N. H.
Published: April 2021

The structure of the pituitary of the adult skate is described. This gland shows two distinct regions of growth which can be correlated with increase of size of the animal. The pars anterior can be subdivided into three regions differing by the staining reactions of their constituent cells: (a) an anterior region where deep-purple chromaphil cells are found; (b) a middle, where they are faintly basiphil; and (c) a posterior, where they are mainly acidophil. It is suggested that these regions are homologous with the pars tuberalis, basiphil, and oxyphil areas respectively of the pars anterior of the mammalian pituitary. The oxyphil cells show an iodine-leucobase reaction similar to that given by the oxyphil cells of the ox pituitary. The ventral lobe is a completely separate structure from the pars intermedia, although it may run along the ventral surface of the latter for some distance. The histology of the neuro-intermediate lobe is described.
Some Points in the Development of Neomysis vulgaris
Authors: Needham A. E.
Published: April 2021

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

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

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

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

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

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

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

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

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.