bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Reno-pericardial Canals in Patella
Authors: Goodrich Edwin S.
Published: April 2021

Strange indeed, and happily unique in the annals of comparative anatomy, has been the history of our knowledge of the reno-pericardial canals of Patella. Although discovered more than thirty years ago, and investigated by many observers since, not only is their structure insufficiently known, but their very existence has been called in question, and even positively denied !
The Molluscs of the Great African Lakes. III. Tanganyikia rufofilosa, and the Genus Spekia
Authors: Moore J. E. S.
Published: April 2021

On the coast line formed by the red sandstone and conglomerate precipices which flank the picturesque shores of Lake Tanganyika there are to be found a number of rock molluscs, which dwell upon the submerged stones, much in the same manner as the periwinkles do upon the half-tide rock faces of the ocean coasts. Of these small Gastropods, what have appeared to be at least three distinct species have been known, but hitherto only by the characters of their empty shells, and in the absence of all other information they have been regarded by the conchologists as approaching the genus Lithoglyphus.1 In the literature, one of these forms, L. neritinoides, still bears that generic name, but the species rufofilosa was eventually placed by Cross in what he supposed to be an allied but separate genus, under the name of Tanganyikia, while the original L. zonatus was placed by Bourguignat in the genus Spekia.
Further Study of Cytological Changes produced in Drosera
Authors: Huie Lily H.
Published: April 2021

This research is an expansion of that previously undertaken, of which an account has been given in this Journal, vol. 39.
On the relation of the Mitochondria and Golgi Apparatus to yolk-formation in the Egg-cells of the common Earthworm, Lumbricus torrestris
Authors: Harvey Leslie A.
Published: April 2021

The yolk-nucleus is merely a mass of mitochondria. The mitochondria arise as a cap of threads over the nucleus, and this cap grows in size and density, migrates away from the nuclear membrane and breaks up into its component mitochondrial threads. These threads become evenly spread throughout the cytoplasm of the cell. The mitochondria are not clearly defined in the very young oogonia. The Golgi apparatus consists of numbers of Golgi elements lying separate in the cytoplasm. There is never any attempt at concentration of these elements round one central mass. The Golgi elements are probably little platelets or spheroids somewhat resembling blood corpuscles in shape. They are not rods. As fixed by Da Fano technique, each element is a little plate with a very lightly impregnating centre and a very heavily impregnating rim. The Golgi elements may probably arise from the cytoplasm. The nucleus contains two nucleoli; an early arising karyosome, homogeneous and solid in structure, and a plasmosome arising later. This plasmosome is liquid in consistency and contains an argentophil core. The karyosome disappears before the oocyte is half grown, but the plasmosome remains in the nucleus while the egg remains in the ovary. No visible nucleolar extrusions into the cytoplasm were observed. Yolk probably arises from the cytoplasm ; no direct metamorphosis of either mitochondria, Golgi apparatus, or nucleolus into yolk was observed.
The Crystalline Style in Gastropods
Authors: Mackintosh N. A.
Published: April 2021

1. Whereas in Lamellibranchia a crystalline style is very common, in Gastropoda it occurs in a few genera only.

2. Crepidula possesses a crystalline style contained in a sac which is partially differentiated from the intestine, being separated therefrom by dorsal and ventral typhlosoles.

The stomach bears a gastric shield and a peculiar groove which is the continuation of the oesophagus. The head of the style lies in the anterior part of the stomach and impinges on the gastric shield.

3. The epithelium of the style-sac consists of densely ciliated cells of moderate length in which the internal rootlets of the cilia extend through the length of the cell and become greatly thickened at the base. The epithelium is specially characterized by the presence of an ‘intra-epithelial ‘network of canals containing numerous fibres whose function is probably a mechanical one. The same structures are present, though less prominent in the epithelium of the typhlosoles, the cells of which are longer and narrower than those of the style-sac epithelium.

4. The crystalline style is a straight transparent. rod of gelatinous consistency. It is built up of co-axial layers surrounding a spiral core. It is composed principally of globulin and contains an amylolytic enzyme.

Food is brought to the stomach embedded in a stream of mucus which becomes entangled with the head of the style. The function of the style appears to be to mix together the contents of the stomach and to supply a starch-splitting enzyme.

5. The crystalline style and style-bearing region of Crepidula resemble in great detail those of certain Lamellibranchs in respect of the shape, proportions, and structure of the stylesac, typhlosoles, and intestine, of the presence of a gastric shield and of the form, composition, and function of the style.

6. The crystalline style in Gastropods may be classified under the same three types as are distinguished in Lamellibranchs in respect of the relations between the style-sac and intestine.

A list of Gastropods is given in which a style is known to occur, and a brief account is given of the various forms assumed by the style and style-sac in this class.

7. The crystalline style of Crepidula resembles that of Lamellibranchs in such detail that this organ must be regarded as strictly homologous in the two groups. It is to be supposed either that it has been lost in all but a few Gastropods, or that its appearance in this group is to be explained on the principle of orthogenesis.

8. In view of the fact that the food of Crepidula is identical with that of the oyster, the retention or appearance of a style in certain Gastropods might be correlated with the feeding habits. Investigations in this direction, however, have not met with very definite results.
The Golgi body in the Erythrocytes of the Sauropsida
Authors: Bhattacharya D.R. , Brambell W. Rogers
Published: April 2021

In recent years the Golgi bodies have been described in so many categories of cells of vertebrates and invertebrates that it has been suggested (3) that it is always present in the animal cell. Cowdry (1), sceptical about this generalization, cites as an exception the non-nucleated red blood-cells. On account of this controversy we examined the erythrocytes of tortoises and birds by the latest methods. This study led one of the authors (D. R. B.) to the discovery of what we believe to be true Golgi bodies in the red blood-cells of the tortoise. More recently the other author (F. W. R. B.) found similar bodies in avian erythrocytes. We have also observed a similar Golgi apparatus in the red blood-cells of the lizard, Uromastix hardwicki. We have not at present extended our study to other classes of vertebrates, but in view of the phylogenetic relationships existing between the Sauropsida and the other classes it seems probable that Golgi bodies will be found to occur not only in the nucleated red blood-corpuscles of the fishes and amphibians, but also in the non-nucleated red bloodcorpuscles of the mammals, at least in some stages of their development. In the young, nucleated red blood-cells of mammals, the mitochondria are abundant, but these, along with the nucleus, disappear pari passu with the later differentiation of the cell (2). It must be remembered, however, that the fully differentiated mammalian red blood-corpuscle is not, strictly speaking, a cell according to the old definition of Leydig (4) and Schultze (5). It is therefore possible that the Golgi elements, if present in the younger stages of the mammalian red blood-cells, may undergo a similar change.
Observations on the Origin of the Germ-cells of the Fowl (Gallus domesticus), studied by means of their Golgi bodies
Authors: Woodger J. H.
Published: April 2021

In 1908 Dantschakoff (4), in studying the development of the blood-cells in the Fowl, observed that certain large cells were budded off from the germ-wall endoderm in front of the primitive streak, to which she gave the name ‘endodermal wandering cells Later, when the mesoderm penetrated this area and blood islands and vessels developed in it, she found that the endodermal wandering cells penetrated the walls of these vessels and were carried round in the circulation. At the stage of about twenty-one somites these cells disappeared from the blood-stream, and Dantschakoff concluded that they took no part in blood development. She described them as being larger than the blood-cells, with many yolk-spheres, and often showing pseudopodia.
On the Structure and Growth of the Ovarian OVUM in Gasterosteos Leiurus
Authors: Ransom W. H.
Published: April 2021

I Purpose to speak in this paper of some points upon which I have been led to adopt conclusions at variance with those generally accepted on the mode of growth and structure of the early vertebrate ovum, not to discuss the whole question.
On some of the Microscopic Effects of the Electric Spark
Authors: Lewis R. T.
Published: April 2021

In the early part of last December I called upon a friend, who showed me an improved form of induction-coil, which, from the peculiarity of its construction, was capable of giving much more brilliant results than instruments of the same size made in the ordinary way. In the course of a number of experiments with this coil, my friend held a card in the path of the sparks between the terminals ; and although these were several inches apart at the time, every spark passed through the card, making the well-known raised burr round each perforation. This done, he tossed the card to me, saying in joke, “There, I’ll make you a present of that as a memento.” On reaching home, my microscope being at hand, I placed the card upon the stage to see what might be the microscopic peculiarities, if any, of the burrs surrounding the perforations. My attention was, however, at once arrested Ly observing that the shape of the holes themselves was not circular, as might have been expected, but clearly and sharply pentagonal.* Many holes were filled up by portions of disrupted fibre which had fallen into them; others had been made in so oblique a direction that their actual shape could not be very well made out ; but the remainder—some thirty in number—were, as I have stated, five-sided ; and the question at once arose, to what cause is this peculiarity of shape due ?
On the Structure and Physiology of the Retina
Authors: Schultze Professor Max
Published: April 2021

The paper of which we here give an abstract has just appeared in the last number of the author’s ‘Archiv f. Mikroskop. Anatomie,’ in which it occupies more than 100 pages, and is illustrated with eight quarto plates. It is undoubtedly one of the most interesting and important contributions to our knowledge of the very difficult structure of which it treats that has ever appeared, and it may be taken as giving an almost exhaustive account of all that is known on the subject, together with much, more especially in the physiological part of the subject, altogether new ; and we deeply regret that our space prevents our giving a more lengthy notice of its contents, or, what would have been very desirable, a complete translation of it.
On Pleurosigma, Donkinta, Toxonidea, and Amphi-Prora
Authors: Barkas T. P.
Published: April 2021

It is my intention this evening to direct the attention of the members of the club to four closely allied genera of diatomaceæ which have recently been found on that part of the Northumberland coast which is in close contiguity to the Mouth of the Tyne. Two of the genera are well known to microscopists ; one has only recently been discovered and named by Dr. Donkin, and the other, which was discovered by Dr. Donkin, and enrolled by him among the Pleurosigmata, was finally constituted into a new genus, and named by Mr. Ralfs, Donkinia, in honour of its discoverer.
Remarks on the Publication of New Genera and Species from Insufficient Material
Authors: Kitton Mr. F.
Published: April 2021

I Have the honour this evening of calling your attention to the growing desire of students of natural history, and more particularly of microscopical observers, for the discovery and description of new genera and species, in consequence of which desire our floras and faunas are encumbered with names and synomyms, two thirds of which have no claim to be there at all. This evil has been, and still is, most virulent amongst the students of the Diatomaceæ, probably because the Diatomaceæ have attracted the attention of a larger number of microscopic observers than any other class of minute organisms. Professor Ehrenberg unfortunately adopted the plan of constituting new genera and species from mere fragments; and however allowable it may be for geologists to make genera and species of the fragmentary remains of the organisms of past epochs, it is surely not desirable that recent forms, occurring as fragments only, or even in small quantities, should be made into new species.
An account of a trichopterous larva
Authors: Tomes C. S.
Published: April 2021

During the early part of the summer of 1866 the larvæ which I propose to describe were noticed in the midst of a mass of Confervæ growing in a pond at Hampstead. Several specimens were at that time kept under observation, but were not then described, as I hoped to succeed in tracing them to their adult form. As I have little hope of again obtaining specimens, the pond having since been drained, I now venture to offer a brief account of them, there being, so far as I have been able to ascertain, no careful description as yet published.
Studies on the Organization and Development of Scorpions. 5. The Lungs.1
Authors: Pavlovsky E. N.
Published: April 2021

The lungs of scorpions have been repeatedly investigated by different authors, both in respect to their structure (Maeckel, 1810 ; Treviranus, Müller, 1828 ; Dufour, 1856 ; Newport, 1845 ; Blanchard, 1851 ; Lankester, 1885 ; Berteaux, 1889; Laurie, 1896 ; Kraepelin, 1905; Haller, 1911) and development (Ganin, 1867 ; Metchnikov, 1871 ; Kowalevsky and Shulgin, 1886 ; Brauer, 1895 ; Laurie, 1890-1 ; Pezeya-slawzewa, 1907). In describing the results obtained in my investigations of the lungs I shall deal only with facts that have been established by myself. The scheme of the structure of the lungs in scorpions being generally known I shall not refer to it here. It should only be noted that hitherto no attention has been directed to the structure of the posterior margin of the stigmata, which is covered with chaetoids of different forms. I distinguish the following : (1) the smooth margin of the stigmata, slightly ruffled (in transverse section) interiorly to the point of attachment of the post-stigmal muscle (Gros-phus madagascariensis, fig. 16, Pl. 12) ; (2) the tuber-culate margin (with low tubercles in Lychas [fig. 17, Pl. 12], Isometrus, Scorpiops, and Uroplectes); (3) the columellar margin with columellae rounded at the apex in Teuthraustes (fig. 20, Pl. 13), Broteas, Broteo-chactas, Uroctonus, and Buthus acutecarinatus (fig. 18, Pl. 13) ; (4) the saw-edge, in section resembling a picket-fence with triangular protuberances the bases of which are adjacent to each other (Vejovis, fig. 22, Pl. 13) ; (5) the barbate margin with fine sharp spines standing separately from each other (Buthus caucasiens, B. australis, B. eupeus, B. emini, Liobuthus [fig. 19, Pl. 13], Anomalobuthus, Orthochirus, Centrurus [fig. 21, Pl. 13], Tityrus, Odonturus, Chaerilus, Hadrurus, Testylus, Brachistosternus); (6) stumpy margin with chaetoids in the shape of columellae widening towards the end (fam. Scorpionidae, fig. 23, Pl. 13). Of these forms only the last-named stigma differs sharply from the rest ; it is present only in the scorpions of the fam. Scorpionidae. The remaining forms are connected with each other by transitional ones, such as the barbate-columellar stigma of Calchas. An analogous structure of the stigmata is also observed in other air-breathing Arthropods (e. g. Thelyphonus, Juins, insects). In all cases the role of the chaetoids of the stigmata appears to be the same. They may serve (1) for mechanical detention of dust particles (in some preparations they were indeed obstructed), and (2) for closing the stigma tighter.
Cytological Observations on Haplosporidium (Minchinia) Chitonis
Authors: King Seana D.
Published: April 2021

The Golgi bodies are concentrated in the form of a juxta-nuclear mass in the uninuclear individuals formed by breaking up of the plasmodium, also in the sporoblast, young spore, and probably in the plasmodium stages. In the mature spore they become scattered, possibly giving rise to fatty reserve material.

The cytoplasmic sphere found in the sporoblast and young spore is that portion of the cytoplasm surrounded by the Golgi bodies. Nothing similar is found in the other stages of the life-cycle.

The details of the life-history are not yet clear. No sexual process has been recognized, and the question of the origin of the sporoblasts is still vague.
Studies on the Vertebrate Head: II. The Orbito-temporal Region of the Skull
Authors: Beer G. R. de
Published: April 2021

It is impossible to summarize the results and conclusions arrived at in this paper completely without occupying too much space. The following are the main points :

The skull is remarkably uniform in all vertebrates, the differences being mostly of detail. With the assistance of the conception of a schematic skull, the conditions in all can easily be made out. The view that the ala temporalis is partially homologous with the ascending process is supported. The view that the so-called 1 Alisphenoids ‘of Tel eos tomes, reptiles, and birds are not homologous with the mammalian alisphenoid is supported. The basitrabecular process has been traced throughout the fish. The morphology of the trigemino-facialis chamber and myodome is described. Allis’s theory of the trigemino-facialis chamber is discussed. The lateral commissure is not to be confused with a prefacial commissure, and it is not homologous with the otic process. Distinct polar cartilages are found in Scymnus. In Scymnus the pila prootica is shown to arise behind the polar cartilage from the anterior region of the basal plate. The dorsum sellae, acrochordal, or prootic bridge are not part of the original skull-floor. In Amia (41 mm. stage) well-marked basal and otic processes are carried by the pterygoquadrate, which extend nearly but not quite to the basitrabecular process and auditory capsule respectively.
Protandry in Teredo Norvegica
Authors: Yonge C. M.
Published: April 2021

Although in the accounts of the Teredinidae given by Caiman (1) and others it is stated that some species are reported to be hermaphrodite while in others the sexes are separate, so far as I have been able to discover the only species which up to the present has been shown to be hermaphrodite is Xylotrya gouldii. Sigerfoos (3), describing the reproductive organs of this species, says, ‘ In the adult ship-worm the sexes are separate. Young specimens (1-4 cm. long) of Xylotrya gouldii, however, are very frequently hermaphrodite. As in all such cases the sperms are developed first, it appears that the species may be protandrous.’ Pelseneer (2) states that,’ In the genus Teredo there is hyperpolygny, the males being only in the proportion of 1: 500 to the females ‘, but he says nothing about their being hermaphrodite nor does he give any details as to species.
Studies on the Golgi Apparatus in Gland-Cells. III. Lachrymal Glands and Glands of the male Reproductive System.
Authors: Bowen Robert H.
Published: April 2021

In this paper the purely descriptive account of the Golgi apparatus in various gland-cells, begun in the first two of these ‘ Studies’ (Bowen, 1926 a and b), will be concluded. A general discussion of the results will be deferred to a succeeding paper, in which I propose to consider the whole problem of the Golgi apparatus in its possible relations to secretion. The technical methods employed for this study are the same as those outlined in the first paper of this series, to which reference may be made for details. It is sufficient merely to note that the osmic-acid method of Kolatchev as modified by Nassonov (1924) has been used exclusively, followed commonly by a counterstain—usually acid fuchsin and aurantia.
The Structure and Development of the Thymus in Fish, with special reference to Salmo Fario
Authors: Deanesly Ruth
Published: April 2021

Three thymus ‘buds ‘can be originally distinguished in trout, in the thickened epithelium above the 1st, 2nd, and 3rd gill-arches, at the junction of ectoderm and endoderm. Differentiation spreads almost immediately into the ectoderm between the original buds, and a continuous differentiating area is formed which is partly ectodermal and partly endodermal. Repeated division of the epithelial cells, beginning a few days before hatching, gives rise to the small thymus cells. The latter are not derived from immigrating lymphocytes, as has been stated by Hammar and Maximow. Emigration of thymus cells may take place at all ages. Immigration of connective tissue and vascular elements from the mesoderm begins just before hatching, but such immigration is not active till a week later. The large elements in the adult thymus are mesodermal, with the exception of the epithelial cells at the edges, and a few mucus gland-cells, similar to those occurring in the ordinary epithelium. In both male and female trout the thymus undergoes almost complete involution, when the fish is between 2 and 2| years old. There is no evidence that the time of involution is connected with the time of sexual maturity.
Further Notes on the Gametogenesis and Fertilization of Sponges
Authors: Brontë Gatenby J.
Published: April 2021

Fertilization. All the early stages of fertilization which previously I was unable to find have been described.The ripe spermatozoon within the collar-cells of Sycon cilia turn has been found.The spermatozoon in all cases examined lies towards the basement side of the cell (figs. 5 and 6, Pl. 19).The enlargement of this flagellate filiform spermatozoon into the oval structure found in the sperm nurse-cell (fig. 7, Pl. 19) has been followed (figs. 3, 4, 6, 8, Pl. 19).The cytoplasmic elements of the sperm nurse-cell have been described (fig. 7, Pl. 19).A later stage in fertilization showing the male pronuclear centrosomes has been-figured (fig. 12, Pl. 20). Cell Granules of Sycon and Grantia.The ‘chromidia ‘of Dendy are regarded as mitochondria (fig. 8, Pl. 19; figs. 9, 12, Pl. 20).A remarkable process of fragmentation of choanocyte 1 chromidia ‘or mitochondria to form peculiar spheres is described (figs. 21, 22, 24, 26, Pl. 21).The granules of the eggs of Sycon cilia turn have been described (fig. 1, Pl. 19; fig. 18, Pl. 21).Some new facts regarding the Golgi elements have been ascertained (figs. 14, 15, and 16, Pl. 21). Spermatogenesis of Grantia.It is claimed that spermatogenesis in Grantia compressa may take place in two ways. First, from definite pockets of cells, lined by large cells, lying in the matrix, as described by Gôrich and myself. Such areas to be regarded as testes. Second, from a direct rapid metamorphosis of collar-cells into spermatocytes.The behaviour of the granules in such cases is figured in figs. 21-6, Pl. 21. In fig. 23, Pl. 21, is a supposed pachytene stage.This metamorphosis involves the whole flagellated cavity, as in fig. 19, Pl. 21, each cell being like the one drawn in fig. 22, Pl. 21. The nucleus of this is like that of spermatocyte, and unlike a collar-cell nucleus. The collar is lost, but the flagellum remains.
The Muscles of the Adult Honey-bee (Apis mellifera L.)
Authors: Morison Guy D.
Published: April 2021

Whilst the anatomy of the bee has been described in detail in many languages and in many thousands of publications, there is yet a gap in the literature for a complete account of the detailed histology and physiology of its muscles. Such a work is necessary as a basis for the investigation of the pathological changes of the muscles in some diseases of adult bees. Part I (‘The Healthy Muscles of the Adult Honey-bee’) of this paper is submitted as a contribution towards filling the gap, and as an introduction to Part II (‘The Pathological Muscles of the Adult Honey-bee’), which will deal with the pathological changes observed in some diseases of adult bees. Owing to the length of Part I it has been necessary to divide it into three sections, of which the first (the following paper) will deal with the somatic musculature, the second with the other muscle systems and the physiology, and the third with the chemistry of the muscle.
Some Notes on the Mucous and Skin Glands of Arion ater
Authors: Barr R. Aileen
Published: April 2021

The pedal gland is an internal aggregation of mucous cells, whose products form a locomotory slime track, and are expelled from the gland by ciliary action in the excretory canal of the gland, and by contractions of muscular fibres among the cells and’by the movements of the foot. The pedal gland of Arion is intermediate in position and structure between that of Limax and that of Milax. The caudal gland is an aggregation of mucous and calcic cells at the posterior end of the body. Its secretion is used, in the young stages, to form a slime thread for descent; during the period of sexual activity the slime gland becomes much more active, probably owing to the influence of the developing sexual organs. Its secretion is devoured mutually by slugs about to copulate. There is an aggregation of unicellular mucous glands on the outer side of the peripodial groove, which I propose to call the peripodial gland. This pours out its secretion on to the foot-fringe and into the peripodial groove, an open ciliated channel which carries the mucous secretion of the body down to the caudal gland. The skin of A r i o n contains mucous, calcic and pigmentary glands which are most numerous on the mantle margin and foot-fringe. The mucous cells provide a secretion all over the body, especially on any ciliated region, which keeps the integument moist. The calcic concretions are probably an excess of lime formed by the calcic cells, which in a shelled species would be employed in building up the shell. They may exercise a protective function, as do the spicules of sponges. The black pigment cells, or chromatophores, are minute irregular cells found just under the epithelial layer, and are often clustered round the blood lacunae. It is probable that the black pigment is produced as a degeneration product of the blood. The red pigment is not contained in special cells but lies in the dermal mucous glands and intercellular spaces. It is probably a compound produced by a lipochrome and the lime of the calcic cells, and it is stored in the tissues in default of a shell on which it might be deposited. It is excreted, possibly as a waste product from the body, along with the body mucus.
Hermaphroditism in Bhyscotus, a Terrestrial Isopod
Authors: Jackson Harold G.
Published: April 2021

The Rhyscotinae are shown to be a non-parasitic hermaphrodite sub-family of terrestrial Isopods. They are protandrous, the ovaries and oviducts making their appearance as individuals approach the female phase. The male external genitalia, vesiculae seminales, vasa deferentia, and a vestige of testis are retained throughout life. The facts are discussed in connexion with other forms, and the possibility of a cyclical alternation of sexes considered.
The Rôles of the Nurse-cells, Oocytes and Follicle-cells in Tenthredinid Oogenesis
Authors: Peacock A. D. , Gresson R. A. R.
Published: April 2021

Since Buchner’s important researches on the hymenopterous egg (1) there does not appear to have been any study, until the present one, which follows up that part of his work relating to oogenesis in sawflies (Tenthredinidae). Buchner was interested particularly in the hymenopterous accessory nuclei, and the larger picture of sawfly oogenesis was left far from complete.
The Effect of a Temperature Gradient on the Early Development of the Chick
Authors: Tazelaar Maria A.
Published: April 2021

Owing to the difficulty of ascertaining the exact position of the embryo in the egg there was much waste of material. Hens’ eggs are not ideal for temperature gradient experiments, for the mean between the temperatures which can be used is below normal incubation temperature. The egg of a coldblooded animal would be far simpler to deal with. The part most easily affected by a temperature gradient was the area vasculosa and its blood-vessels. This was to be expected, since the size of this extra-embryonic part is not strictly limited; the arrangement of the blood system of the area vasculosa was also modified in some cases. Slight disproportion of parts was effected in some cases. The head was sometimes slightly more developed than the posterior end, and in some cases the posterior limbs were precociously developed. Differences in size between the limb buds on each side also occurred. The ratio of embryo to primitive streak was decreased considerably in the case of two embryos, treated with antagonistic gradients. In some embryos treated with a lateral temperature gradient the somites had become shifted up on the heated side. The greatest effect was obtained in an embryo whose somites of one side alternated with those of the opposite side. It is possible that this condition may be regulated after normal incubation ; results, however, were too few for certainty. The numbers used were not sufficient for the conclusive determination of the degree of regulation which experimentally treated embryos underwent. However, all late stages when examined were normal ; whether these cases were correctly treated or not it is impossible to say.
Memoirs: Lipin Secretion in the Elasmobranch Interrenal
Authors: FRASER A.H. H.
Published: April 2021

1. The occasional occurrence of an intimate anatomical relationship between the interrenal and chromaffin tissue is described.

2. It is shown that in addition to the ordinary lobule commonly figured, the interrenal may show hypertrophied lobules, disintegrating lobules, and acini. These various histological pictures are interpreted as being various phases in a definite cycle of glandular activity, viz.:

(1) Resting lobule.

(2) Distension of lobule.

(3) Disintegration of lobule.

(4) Formation of acinus.

(5) Collapse of acinus.

(6) Reformation of resting lobule.

3. Evidence is advanced of a massive secretion of lipin into the interlobular capillaries. The importance of this phenomenon is emphasized.

4. The occurrence of melanin pigment in a minority of the glands is described, and evidence submitted of a relationship between the formation of melanin and the secretion of lipin.
Mitochondrial Behaviour during the Life-cycle of a Sporozoon (Monocystis)
Authors: Horning E. S.
Published: April 2021

Observations show that mitochondria are capable of arising de novo in the freshly liberated sporozoite stage of the life-cycle of Monocystis. Mitochondria are present in large numbers throughout the course of the asexual phase of the life-cycle. During the conjugation of the gametocytes the rod-like mitochondria give rise to numerous spherical bodies. At fertilization the mitochondria within the gametes appear to fuse, resulting in the formation of larger clumps. At the commencement of the spore phase the mitochondria gradually decrease in numbers, and are totally absent within the mature spore. Later, the growth of the liberated sporozoite or young trophozoite is accompanied by a reformation and rapid reproduction of mitochondria. The disappearance and reformation of mitochondria during certain stages of the life-cycle may be correlated with their apparent synthetic activity.
On the Development of the Mid-Gut in the Larval Stages of Vanessa urticae (Lepidoptera)
Authors: Henson H.
Published: April 2021

The mid-intestine of Vanessa urticae has three separate categories of cells, interstitial cells, goblet cells, and ordinary columnal epithelial cells. The interstitial cells renovate the epithelium by the addition of new cells at each larval ecdysis. There is a period at the beginning of each instar during which cell differentiation occurs (from interstitial nests). This process soon ceases. Cell division by mitosis occurs amongst the interstitial cells throughout the instar. No good evidence could be obtained that the goblet cells and columnar cells are homomorphous. The goblet cell cannot become a columnar cell because it undergoes a cycle of growth and differentiation which diverges increasingly from the columnar type. Similarly the goblet cells cannot be derived from senescent columnar cells because they are present at the time of hatching. Both are derived by independent modification of interstitial cells and are therefore dimorphous. The goblet cells contain material which is optically indistinguishable from striated border. It has been shown that in this animal the so-called merocrine method of secretion of the gut cells may not be a secretion process at all. The alternative view that the formation of ‘secretion’ vesicles is really a process of cell disintegration, due to wear and tear, or to the incidence of metamorphosis, is here favoured.
Nucleolar behaviour in the Mitosis of Plant Cells
Authors: Frew Priscilla E. , Bowen Robert H.
Published: April 2021

The resting nuclei of Cucurbita pepo and Cucurbita maxima contain a single, spherical nucleolus that is relatively very large. Part, at least, of this nucleolus persists during nearly the entire process of mitosis. During the metaphase it lies in the equatorial plate and becomes elongated in the direction of the long axis of the spindle, to form first a cylinder and then, with further elongation, a dumb-bell-shaped structure, which finally separates into two fragments that migrate to the opposite poles of the spindle. This entire movement occurs prior to any anaphase migration of the chromosomes. The nucleolar fragments apparently are not included in the daughter nuclei during the telophasic reconstruction, but degenerate in the cytoplasm. Examination of the literature suggests that a similar process of nucleolar division probably occurs in a wide variety of plant-cells. The bearing of this type of nucleolar division on theories of the dynamics of anaphase migration of the chromosomes is briefly discussed.
The Conjugation of a Triploid Chilodon
Authors: MacDougall Mary Stuart
Published: April 2021

The finding of a triploid Chilodon in the cultures of Chilodon uncinatus which had been exposed to the action of ultraviolet rays has been previously reported, MacDougall (1929). The present paper deals with the conjugation of this organism.
The Grigarinis of Cucumaria: Lithocystis minchinii Woodc. and Lithocystis cucumariae n.sp
Authors: Goodrich Helen Pixell
Published: April 2021

In 1906 Woodcock described an interesting gregarine occurring in the respiratory trees of Cucumaria. 1 This parasite is neogamous and so precocious is its association that normal single vegetative forms (trophozoites) have not been seen. Apparently, as Woodcock pointed out, infection takes place by spores being drawn into the respiratory trees with currents of water through the cloacal aperture—a quite exceptional method of contamination, so far as is known. The sporozoites emerging from a ripe spore probably penetrate immediately between the epithelial cells into the connective tissue of the respiratory tree wall and there pair and round off. After absorbing food and growing at the expense of the host, they encyst. The host also forms round each pair of parasites a cyst consisting of several layers of flattened cells. These spherical cysts of various sizes are the most commonly encountered stage of the parasite, and are to be seen as conspicuous opaque white spheres through the wall of the respiratory trees on opening into the coelom. Each cyst contains two nuclei, but generally no partition or other indication of a dual origin. They are quite soft and easily deformable, becoming much flattened when mounted under a cover-glass. These early stages have already been described by Woodcock, who recorded cysts varying from 17 to 2OOµ in diameter. I have been lucky enough to find still larger cysts, many containing spores, other?vise I can add little to his description. Finding nothing but vegetative stages in the respiratory trees, Woodcock was led to connect this parasite with another gregarine, Lithocystis (Diplodina, Cystobia) minchi nii, which he found in the general body-cavity. This protozoan parasite was also fairly common in the Cucumaria that I have examined, and some further description of it is given below (p. 280).
The Formation and Fate of the Operculum and Gill- chambers in the tadpole of Bana temporaria
Authors: Brock Gwendolen T.
Published: April 2021

This work has been undertaken with the object of establishing the exact method of formation of the operculum and gill-chambers in the tadpole. It is also intended to follow up a suggestion of 0. H. Latter (1923) that branchial respiration continues after metamorphosis by means of paired apertures immediately in front of the bases of the freed anterior limbs.
The Neuro-muscular mechanism of the gill of Pecten
Authors: Setna S. B.
Published: April 2021

The gills of Pecten have been the subject of much study, their structure being particularly described by Ridgewood (1903), Kellogg (1915), and Dakin (1909). However, there are structures of profound physiological importance present in the gills which apparently have so far remained unnoticed, while data are lacking concerning the neuromuscular mechanism which leads to a definite and orderly distribution of food material on the gill surfaces. Further, there are only casual references to the sensory reactions of the gill, without which an adequate understanding of their function is impossible. My own observations disagree with those of Kellogg (1915), who writes, ‘Extensive movements of the gills of Yoldia have been described by Drew (1899) and the writer (1890) in which organs there are well-developed muscles, but in the Pecten gill and others also capable of extensive movements such muscles are absent.’
Variation in the Histological Condition of the Thyroid Glands of Sheep with regard to Season, Sex, Age, and Locality
Authors: Lowe Esther
Published: April 2021

Our present knowledge of the thyroid gland has been derived chiefly from the investigations of workers on the human gland. A comparatively small amount of work has been done on the thyroids of the lower animals, and this has been chiefly of an experimental nature, very little attention having been paid to the histology.
The Green Bodies of the Intestinal Wall of certain Chaetopteridae
Authors: Berkeley C.
Published: April 2021

The green bodies in the intestinal epithelial cells of three species of Chaetopteridae, each representing a different genus, have been examined. They are very similar in the three cases and resemble those of Chaetopterus variopedatus. They are frequently motile and flagellated when separated from the intestinal tissue. They represent an infection of an organism which spreads in a flagellated condition. The organism is a flagellate probably belonging to the family Chrysocapsinae. The name Chrysocapsa chaetopteri is proposed for it.
On the unsegmented ovum of Echidna (Tachyglossus)
Authors: Flynn T. Thomson
Published: April 2021

In this communication is described for the first time the unsegmented germinal disc of the monotreme Echidna (Tachyglossus), and measurements are also given of living intra-uterine eggs at early stages Segmentation is not initiated in Echidna until the egg has arrived in the uterus The polar bodies are much smaller than those described for Ornithorhynchus. The first is much larger than the second but, contrary to what has been reported to occur in Ornithorhynchus, remains undivided The germ nuclei, immediately before the formation of the first cleavage spindle, undergo conjugation and fusion. Contrary to what is described for Ornithorhynchus, polyspermy does not normally occur in the fertilization of the ovum of Echidna.
Development of the Sex Glands of Calotes. I. Cytology and Growth of the Gonads prior to Hatching
Authors: Simkins Cleveland Sylvester , Asana J. J.
Published: April 2021

There are two dissimilar and opposing views regarding the origin of the sexual elements in the vertebrates in general, and these dissimilar views are held by workers upon the origin of the reproductive elements in the Reptilia as well. The provisional conjectures are these : first, the forerunners of the propagative elements, the so-called primordial germ-cells, originate outside the fundament of the gonad and migrate to that incipient structure throughout the course of early ontogenesis ; second, the definitive germ-cells arise in the gonad, concomitant with its formation from units directly derived from the germinal epithelium.
The Oogenesis of Calanus finmarchicus
Authors: Hilton Irene F.
Published: April 2021

Three regions can be recognized in the ovary: a multiplication zone containing oogonia undergoing mitosis, a synapsis zone containing the first formed oocytes in the prophases of the maturation division, and a growth zone containing oocytes in a series of growth phases with the nucleus in a ‘resting condition ‘.

The oogonial nuclei contain two or three nucleoli—plasmosome and karyosomes. In the oocytes a single nucleolus is present; this is formed by the fusion of the plasmosome and at least one karyosome and is therefore an amphinucleolus. The chromatin in the oogonia and young oocytes is arranged round the periphery of the nucleus andis aggregated in knots (pp. 196-200).

Nucleolar extrusion begins in the young oocyte and continues throughout the growth period. It is most marked in the young oocytes and in oocytes about to undergo maturation (pp. 200-3).

In the older oocytes the chromatin is in the form of a tangled thread surrounding the nucleolus. Immediately before maturation this condenses and circular chromosomes emerge: these form tetrads (pp. 203-5).

The mitochondria are present in the oogonia and very young oocytes in the form of a cap lying upon the surface of the nuclear membrane. The mitochondrial elements spread and multiply until they surround the nucleus as a ring; afterwards they disperse and are distributed evenly throughout the cytoplasm. They swell up and finally yolk-droplets appear in their place (pp. 207-11).

Yolk-formation usually begins in half-grown oocytes, but is sometimes earlier. The formation of yolk-droplets begins at the periphery of the cell and proceeds inwards. It is suggested that yolk is formed by transformation of the mitochondria and the deposition in them of substances derived from the cytoplasm and the nucleolus. The cytoplasm is flocculent in the young oocytes, granular in the half-grown oocytes, and filled with fluid vacuoles in mature oocytes. It passes from a primary condition of oxyphily to basophily and finally back to a secondary oxyphil condition in mature oocytes (pp.211-13).

In the young oocytes deeply-staining spherical structures were seen adjacent to the mitochondrial cap. From their appearance it is possible these bodies represent the Golgi apparatus, but Da Fano fixation failed to demonstrate them. In half-grown oocytes the apparatus was visible in the complex condition at one side of the cell. As growth proceeds it passes from a complex to a diffuse condition and in mature oocytes the Golgi elements are uniformly distributed throughout the cytoplasm (pp. 213-15).
The Cranial Characters of the Brevicipitid Genus Cacosternum (Boulenger)
Authors: de Villiers C. G. S.
Published: April 2021

The present paper is a continuation of my work on the cranial characters of the two South African Brevicipitid genera lacking the claviculo-procoracoidal arch in the pectoral girdle. The genus Phry nomerus (Noble) was discussed in a previous paper in this Journal (vol. 73), to which the reader is referred for details of technique, which was, however, slightly varied for purposes of the present research, inasmuch as double bulkstaining was resorted to. The nuclear stain, haemalum, was applied in the usual way, and after all traces of alum used for differentiation were washed out, the object was bulk-stained for twenty-four hours in a strong aqueous solution of Bismarck brown and differentiated in ordinary tap-water for forty-eight hours. I have not yet experimented with bulk-staining for connective tissue and muscle; stains recommended for this purpose are fuchsin and light green or eosin respectively. The use of van Gieson in conjunction with Bismarck brown is considered by many workers to lead to confusing results, so that pure fuchsin is recommended for connective tissue and for decalcified bone. All material was decalcified with Ebner’s solution in preference to nitric acid, which is, however, used with great success for the same purpose by Professor Stadtmiiller of Gottingen, according to a personal communication from him. The material of Cacosternum bottgeri was kindly supplied by the Director of the Transvaal Museum; Cacosternum capense was collected by the author on the Stellenbosch Flats after the first rains in May 1928. The eighteen specimens collected are the only ones known besides the type specimens collected by Mr. Rose of Cape Town. Three specimens of Cacosternum namaquense were collected by Dr. Herre of Stellenbosch University during the phenomenal Namaqualand rains of 1929; but owing to the rarity of the material, this species was not microtomized. Mr. Hewitt has recently upheld the species and recorded the existence of two specimens referable to it in the collection of the South African Museum.
The Scientific Work of Edwin Ray Lankester
Authors: Goodrich Edwin S.
Published: April 2021

The death on August 15, 1929, of Sir E. Ray Lankester, formerly Editor of this Journal, was announced in the November number of vol. 73, 1929.1 Lankester’s long connexion, as Co-Editor, as sole Editor, and finally as Honorary Editor, with the ‘Quarterly Journal of Microscopical Science’ has already been dealt with by A. Sedgwick and W. F. R. Weldon in the complimentary number dedicated to him on the occasion of the twenty-fifth year of editorship (no. 141, vol. 36, 1894), and again on his seventieth birthday by G. C. Bourne (no. 253, vol. 64, 1919).
Observations on Dicystid Gregarines from Marine Worms
Authors: Mackinnon D. L. , Ray H. N.
Published: April 2021

Two species of the dicystid gregarine Polyrhabdina Mingazzini have been studied in polychaete worms from Plymouth. Polyrhabdina spionis is not the organism described by Kölliker as Gregarina spionis, and should be named Polyrhabdina spionis Mingazzini. We do not consider that the epimerite of Polyrhabdina spionis is intracellular, nor do we believe that it is an amoeboid and food-absorbing structure. The specimens we have found in Scolelepis fuliginosa differ in other details from those described by Caullery and Mesnil in the same worm from another locality, and may constitute a new variety. The dicystid gregarine from the intestine of Polydora flava is described by us. This may be the organism called by Caullery and Mesnil Polyrhabdina polydorae, but we do not agree that this name is synonymous with Doliocystis polydorae Léger. We describe two new dicystid gregarines from the intestines of the echiurid worm Thalassema neptuni Gartner at Plymouth. These we have named Hentschelia thalassemae n.gen., n.sp., and Lecythion thalassemae n.gen., n.sp. Association was frequently observed in the gregarines from Thalassema. The gametocytes do not normally develop further until they have been passed out with the excrement. In sea-water a cyst is formed and spores developed. Anisogamy, with flagellated male gametes, has been observed. The dicystid gregarines are a heterogeneous group. Those with simple, transitory epimerite may be related to the acephalines; but the species dealt with in this paper are almost as complicated in structure as tricystids, and seem to differ from these only in the absence of a septum dividing a protomeritic from a deutomeritic segment.