bluuebunny/crossref_metadata_2025 huggingface dataset:
Notes on some Aquatic Oligochæta
Authors: Benham W. Blaxland
Published: April 2021

During the present spring (1891) I had under observation at various times a number of aquatic Oligochæta, for the purpose of illustrating my lectures to the students here who were working at the group; and I came across several interesting facts, some of which are worth recording in these pages.
On the Differentiation of Leprosy and Tubercle Bacilli
Authors: Slater Charles
Published: April 2021

In the course of an investigation of a case of tubercular leprosy the question arose as to the nature of certain lesions of the lungs. It is well known that patients suffering from leprosy frequently succumb to an affection of the lungs closely resembling ordinary phthisis. Whether this phthisis is the result of an intercurrent tuberculosis, or is of the same nature as the undoubtedly leprotic lesions of viscera other than the Iings, is still a matter of dispute. While certain observers, such as Hansen, Neisser, and Leloir, regard the phthisis as an intercurrent disease attacking a weakened patient, others, as Bonomé and Arning, think that the lesions are due to the spread of the leprotic process to the lungs. As a subsidiary branch of the inquiry it was thought advisable to examine the statements of previous investigators as to the differential staining and morphological differences of the bacilli present in the two diseases, and to test their results on material supplied by this undoubted case of leprosy.
The Development of the Oviduct in the Frog
Authors: MacBride Ernest W.
Published: April 2021

The investigation which forms the subject of the present memoir was commenced in July, 1890, at Mr. Sedgwick’s suggestion. A collection of tadpoles, which were preserved in the Morphological Laboratory, Cambridge, was first examined without result. None of them showed any trace of the oviduct, though in some cases both pairs of limbs were well developed. Through the kindness of Mr. Sedgwick I was enabled to procure a considerable number of Frogs, in which the tail was being absorbed or had just vanished; and amongst these I found all the necessary stages for my work.
On the Innervation of the Cerata of some Nudibranchiata.
Authors: Herdman W. A. , Clubb J. A.
Published: April 2021

A few years ago (1889) one of us read a paper at the Newcastle-on-Tyne meeting of the British Association “On the Structure and Functions of the Cerata in Nudibranchiata,” in which these dorso-lateral processes were regarded as being probably epipodial outgrowths. In other papers2 published since, we have compared the conditions of these structures in various genera of Nudibranchs, and have tried to show that they are all modifications of simple lateral epipodial ridges. Gars tang also, in papers3 published about the same time, came independently to the same conclusions from the examination of a somewhat different series of forms.
The Larva of Asterias vulgaris
Authors: Field George W.
Published: April 2021

This work was undertaken at the suggestion of Professor W. K. Brooks for the purpose of getting, if possible, some further hint upon the significance of the larval form in Echinoderm phylogeny. It was carried on from October, 1889, to April, 1891; from June to October, 1890, at the Laboratory of the United States Fish Commission at Wood’s Hall, Massachusetts, where the living animals were studied, and for the remainder of the time in the Biological Laboratory of the Johns Hopkins University, where the work was upon the preserved material. My heartiest acknowledgments are due to Professor Marshall McDonald, U.S. Fish Commissioner, for the advantages furnished at the Government Laboratory; and to Professor Brooks, of this university, who has so kindly placed at my service the preserved material, the preparations, and drawings, which formed the basis of his recent paper before the National Academy (4).
On some Parasitical Insects from China
Authors: Giglioli Henry
Published: April 2021

Some time since, Mr. Swinhoe, who has done so much towards advancing our knowledge of Chinese ornithology, presented me with several parasitical insects, which he had met with during his zoological investigations in China. Finding them interesting and mostly new, I thought that a description of them might be useful.
On the Importance of Raphides as Natural Characters in Botany
Authors: Gulliver George
Published: April 2021

It seems amazing that the importance of raphides in vegetable economy, and their great value as natural characters in systematic botany, should have received so little attention. Probably the chief reasons for this neglect are, that these beautiful crystals have been commonly regarded simply as curiosities, rather accidental than essential, and that sphæ-raphides and other forms have been too often confounded with raphides. Hence, indeed, has arisen such confusion that we frequently hear them alluded to merely as microscopic marvels and irregular products; and the character of raphis-bearing, which I have assigned to such orders as Bal-saminaceæ, Rubiaceæ, and Onagraceæ, regarded as worthless. But if we restrict the term raphides, as proposed and defined etymologically in one of my former papers (‘Ann. Nat. Hist.’ for Sep. 1863), taking care to distinguish raphides from sphæraphides, that objection will cease altogether, and the value of raphides, as natural characters, become at once evident. Among British plants, it will be immediately seen what very different things the sphæraphides of Lythraceæ and Haloragaceæ are from the raphides of the intervening order, Onagraceæ; and that, though Oxalis Acetosella is not a raphidiferous plant, it abounds in sphæraphides. Numberless examples of the same kind might be cited.
The Utilization of Minute Life; being Practical Studies on Insects, Crustacea, Mollusca, Worms, Polypes, Infusoria, and Sponges
Authors: Phipson T. L.
Published: April 2021

We cannot give a better idea of the scope and intention of this work than is conveyed in the author’s preface:
“A Contribution to the Minute Anatomy of the Retina of Amphibia and Reptiles
Authors: Hulke J. W.
Published: April 2021

The animals of which the retina was examined were the frog, the black and yellow salamander, the edible turtle, the water- and the land-tortoise, the Spanish Gecko, the blindworm, and the common snake. The method adopted was to examine the retina (where possible) immediately after decapitation of the animal, alone and with chemical agents; and to make sections of the retina hardened in alcohol or in an aqueous solution of chromic acid, staining them with iodine or carmine, and adding glycerine, pure and diluted, to make them transparent. The following is a summary of the results of the examination:
On the Communication between the Cœlom and the Vascular System in the Leech, Hirudo medicinalis
Authors: Goodrich Edwin S.
Published: April 2021

The investigation, of which an account is given in the following pages, was undertaken with the object of ascertaining for certain whether, in the medicinal leech, the cavities of the so-called sinus system do, or do not, communicate with those of the contractile vascular system.
The Anatomy of Pleurotomaria Beyrichii, Hilg
Authors: Woodward Martin F.
Published: April 2021

The vast antiquity which characterises the genus Pleurotoinaria—for no one can doubt the identity of the living and fossil shells which are customarily grouped together under this name—has justly endowed this mollusc with great interest for those studying the ancestry of the Prosobranchia. When, therefore, a living example was obtained by Agassiz in 1871, and later in 1879 several specimens of both P. Quoyana and P. Adansoniana were dredged by the United States steamer “Blake,” the result of an investigation of the anatomy of these forms was awaited with great interest. Unfortunately, however, the specimens all turned out to be in a bad state of preservation, and although falling into such skilled hands as those of Dr. Dall, it was found impossible to make out much of their anatomy. Dall, however, published 1 figures and descriptions of the external characters of the animals, of the radulæ and of some few points in connection with the pallial complex, the rest of the body being too much decomposed for investigation.
On the Structure and Affinities of Saccocirrus
Authors: Goodrich Edwin S.
Published: April 2021

When studying the morphology of the excretory organs of the Polychæta, I thought it advisable to investigate those few cases of worms in which the true nephridia have been alleged to function as genital ducts. Of these Polychætes, Saccocirrus papillocercus, Bobr., is one of the most interesting ; and whilst occupying for a short time last winter, at the Zoological Station at Naples, a table kindly placed at my disposal by the committee of the British Association, I had an opportunity of studying its structure.
The Anatomy of Scalibregma inflatum, Rathke
Authors: Ashworth J. H.
Published: April 2021

My attention was drawn to our scanty knowledge of Scalibregma when discussing the affinities of Arenicola with other Polychætes (1900, 1 p. 544). It was found impossible to make any definite statement regarding the affinities of these two genera, owing to the small amount of information available regarding the structure of Scalibregma. This Polychæte has received little attention from zoologists, perhaps on account of its comparative rarity and the somewhat small size of the majority of specimens in museum collections. Most of the references to this animal in zoological literature are mere records of its capture. There are only three or four memoirs which refer, quite briefly, to some details of its structure, and only one, by Danielssen (1859, p. 69), which contains a connected account of its internal anatomy. This memoir contains no mention of the nephridia, although the accompanying figures show structures which are obviously nephridia, but which Danielssen considered to be ovaries. He also stated that Scalibregma is hermaphrodite, and that its nerve-cord is provided with typical ganglionic swellings. Subsequent authors do not throw light on any of these matters. In these points there was such marked difference between Scalibregma and Arenicola, which in other respects seemed to have much in common, that I was anxious to reinvestigate the anatomy of the former as soon as specimens were available, chiefly with the intention of comparing the nephridia, gonads, and nerve-cord of these two genera. The material placed at my disposal has enabled me to study the anatomy and histology of this northern Annelid, and to determine some interesting points connected with most of the systems of organs.
The Development of Admetus pumilio, Koch: a Contribution to the Embryology of the Pedipalps
Authors: Gough L. H.
Published: April 2021

I began my investigations of the development of Admetus pumilio in November, 1899. During the previous year I had been studying the development of spiders under Prof. A. Goette, in Strassburg.
Notes on the Relations of the Kidneys in Haliotis tuberculata, etc
Authors: Fleure H.J.
Published: April 2021

Numerous accounts of the structure and relations of the kidneys of Diotocard Gastropods have been written, chiefly by workers interested in the question of the homology of the Monotocard kidney, but in the various descriptions occur several contradictory statements, which naturally lessen the value of current theories on the subject. The present paper is the first-fruits of a study of the gastropod kidney, and it endeavours, by throwing new light on one or two disputed points, to help on the solution of this difficult problem. There are also brought forward certain suggestions concerning the kidney and reproductive organs of Monotocards which I feel convinced should be studied together; these suggestions are naturally extremely tentative, pending further work. In making this communication I wish to express my deep indebtedness to Professor Ainsworth Davis, whose advice and encouragement have alone made this research possible.
On a Cestode from Cestracion
Authors: Haswell William A.
Published: April 2021

The Cestode, the results of a study of which are embodied in the present paper, occurs, usually in abundance, in the large intestine of the Port Jackson shark. It is one of these remarkable forms to which attention appears to have been first specially directed by P. J. van Beneden (1 and 2), in which the proglottides are set free from the posterior end of the strobila long before full maturity has been reached, and only attain a stage corresponding to that of the “ripe” proglottides of a Tænia after having pursued an independent existence for some considerable time.
The Anatomy of Pœcilochætus, Claparède
Authors: Allen E. J.
Published: April 2021

Claparède, in his ‘Beobachtungen über Anatomie und Entwicklungsgeschichte wirbelloser Thiere an der Küste von Normandie Angestellt,’ published in 1863, describes and figures (pp. 77—80, Taf. vi, fig’s. 1—11) several stages in the development of an annelid larva, which he was unable at the time to assign to any known genus. This larva was very common in the plankton at St. Vaast, and the same, or a very similar one; had previously been found (in 1855) by Claparède on the coast of Norway. He surmised that the larva must belong to some common worm at that time still undescribed.
A Preliminary Consideration as to the possible Factors concerned in the Production of the various Forms of Spicules
Authors: Woodland W.
Published: April 2021

So many misconceptions prevailing as to the essential nature of spicules, and in consequence as to the causes which can possibly give rise to the multitudinous and remarkable forms which spicules assume, a brief consideration of the subject seems to be called for. Such at least will serve to remove sundry erroneous ideas which are continually being put forward in explanation of these phenomena and will also point out the direction in which further investigation is necessary for their better comprehension.
Researches on the Intestinal Protozoa of Frogs and Toads
Authors: Dobell C. Clifford
Published: April 2021

The observations recorded in the following pages are the results of an attempt to discover the life-histories of the protists which inhabit the gut of the common frog and toad. My original intention was the investigation of the life-history of Trichomonas. But so great is the number of organisms which live in company with this form that I very soon perceived that it would be almost impossible to confine my investigations to a single species. Every organic particle in the alimentary canal had to be tested regarding its possible relationship to the organism which, in particular, I was examining. For example, I not infrequently found a number of cysts occurring side by side with Trichomonas in the frog’s gut. To connect the two, without further evidence, would be ridiculous. I therefore had to discover to what organism the cysts belonged. And thus, time after time, I found myself driven to determine, to the best of my ability, the life-histories of all the protists which I encountered. The number of these is considerable. Therefore there were many difficulties in the way of success, and therefore, also, my work remains still far from finished.
Chromidia and the Binuclearity Hypotheses: A Review and a Criticism
Authors: Dobell C. Clillord
Published: April 2021

Since the seed of the chromidia hypothesis was sown by Richard Hertwig in 1902, it has displayed such an amazing ability to absorb new or previously uncorrelated facts, for its own growth, that it now—in its more mature form—stands out as one of the most conspicuous objects in the whole wide field of cytology. And it has not—one may be allowed to think—merely flourished on the soil where none other could take root : it has also, in so doing, thrown into the shade many a less showy upgrowth. Yet it is not beyond the bounds of possibility that these smaller growths, being rooted in a firmer foundation of facts, may remain to ripen long after the chromidia hypothesis has fallen to the earth— from the sheer weight of its own overgrowth and the insecurity of the ground in which it grew.
The Entry of Zooxanthellæ into the Ovum of Millepora, and some Particulars concerning the Medusae
Authors: Mangan Joseph
Published: April 2021

During the present winter Prof. S. J. Hickson kindly gave me an opportunity of examining1 the material from Jamaica in which he discovered the female Medusas of Millepora (‘99). The results of my inquiry are mainly concerned with the manner in which the symbiotic zooxauthellæ, found to exist in the free ova of that genus, infect the germ cells. I also wish to record the occurrence of free male medusai amongst the free female meduste collected in the above locality, and to make some remarks upon the oogenesis.
On Certain Features in the Development of the Alimentary Canal in Lepidosiren and Protopterus
Authors: Kerr J. Graham
Published: April 2021

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

I was honoured by the request of the Executive Committee to give an address at the first meeting of the Embryological Section of the Seventh International Zoological Congress.
The Eye of Pecten
Authors: Dakin W. J.
Published: April 2021

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

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

In Part 5 of these studies (‘Quart. Journ. Micr. Sci.’ vol. 56, pt. 3, 1911, p. 591) some observations on the fluctuations in size of hens’ combs were recorded, which showed that in adult as well as in young hens the area of the comb may increase or decrease with great rapidity, the greatest increase recorded being 130 per cent, within three weeks. It was proved that these striking fluctuations were independent of any experimental treatment, that they did not correspond with a general increase in weight, and that they appeared to coincide with the egg-laying periods.
Studies in the Experimental Analysis of Sex.
Authors: A. Gcolticy Sinilli, ill.
Published: April 2021

Part 9.—On Spermatogenesis and the Formation of Giant Spermatozoa in Hybrid Pigeons.
The Reproductive Cycle in the Marsupial Dasyurus viverrinus
Authors: Hill J. P. , O’Donogliue Chas. H.
Published: April 2021

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

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

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

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

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

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

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

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

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

The subject of the following notes is a transparent gelatinous-organism, which was at first put aside with other plankton collections as some form of medusa. A subsequent examination, however, proved it to be a Holothurian with several features of special interest..
Protozoa parasitic in Termites
Authors: Cutler D. Ward
Published: April 2021

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

1. Lygocerus testaccimanus, Kieff. is a hyperparasite of A p h i s saliceti, Kalt., through the primary parasite, Aphidius salicis, Hal. ; and L. earneroni, Kieff. is similarly a hyperparasite of Macrosiphum u r t i c a e, Kalt., through the primary parasite, Aphidius c r v i, Hal.

2. The Aphidius is attacked immediately before or after metamorphosis, when lying within the empty skin of the aphis within which it is reared.

3. The egg is laid, and post-embryonic development takes, place, outside the body of the host.

4. The evidence points to the conclusion that there are four larval instars and three moults.

5. The larvae differ in several particulars from those of the families of Proctotrypoidea previously described, and there is considerable difference in form between the early and later instars.

6. During development, which lasts about six days, the larva devours its host, and then pupates within the skin of the aphis for a further period of two weeks.

7. Two, and possibly more, broods are reared in the season ; and it is probable that the hyperparasite is a considerable check on the Asphidius in its control of plant-lice infestation.

8. Lygocerus, though occasionally attacked by its own species, was never found to be parasitised by another hymen-opteron. This immunity is probably due to the active movements with which the larva and pupa in the cocoon respond to external stimuli.
Observations on the Shape of the Nucleus and its Determination
Authors: Champy Christian , Carleton H. M.
Published: April 2021

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

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

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

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

The chondrocranium of the existing specimens of the larval Polypterus have been redescribed, and the earlier specimens figured for the first time. The development of the following structures have not been described previously in Polypterus:

The lateral commissure which forms first from the prootic and then the post-palatine process. The taenia marginales, which arise as distinct cartilages. The development of the visceral arches and the temporary fusion of the first and second hypobranchials and ceratobranchials.

This development is then briefly compared with those of Scyllium, Amia, Lepidosteus, Acipenser, and Teleosts; a strong likeness being shown between it and that of Amia. The view of Goodrich is thus afforded additional support.
Notes on Odontosyllis
Authors: Goodrich Edwin S.
Published: April 2021

During a recent visit to the Biological Station in Bermuda, my attention was drawn to the interesting ‘fire-worm’, Odontosyllis enopla Verrill, by Dr. E. L. Mark, who kindly helped me to obtain living specimens. The strange swarming habits of this Syllid have been described by Galloway and Welch (1916), who have also given a good general account of its anatomy. Certain points which escaped them, more especially concerning the structure of the alimentary canal and nephridia, seem to be worthy of special notice and are here described.
On the Intracellular Micro-organisms of some Bostrychid Beetles
Authors: Mansour K.
Published: April 2021

Bhizopertha dominica, F., Sinoxylon ceratoniae, L., and Bostrychoplites Zickeli, Mars., possess paired mycetomes full of bacteria-like micro-organisms. The transmission of the micro-organisms from one generation of the host to the next is carried out in the following way: Micro-organisms from the mycetomes invade the testis lobes, multiply, and mix with the sperms. These micro-organisms pass with the sperms during copulation into the bursa copulatrix of the female. From this region they pass through the micropyle of the fully formed eggs during their passage to the outside, and thus the infection is accomplished. The invasion of the testis lobes by micro-organisms causes abnormality in the process of spermatogenesis. The micro-organisms in the developing egg are first seen near the micropylar region in the peripheral protoplasm. In a later stage these micro-organisms, which have multiplied greatly by then, are to be found in between the yolk globules towards the posterior pole of the egg. From this stage onwards the course these micro-organisms follow till they reach their final destination in the larva has not been followed. The mycetomes throughout life remain quite isolated from the alimentary tract. The biological relation between the micro-organisms and their host is also discussed.
On the Ptilinum of the Blow-fly (Calliphora erythrocephala)
Authors: Laing Joyce
Published: April 2021

An account is given of the morphology, development, and changes following emergence of the ptilinum of the blow-fly. The ptilinum in Calliphora erythrocephala develops from the integument of the anterior part of the head. Differentiation from the surrounding integument begins first as a local thickening of the epidermis. The structure of the thickened area is similar to that of an epidermal imaginal bud. At the end of the third day after pupation at 25° C. this epidermal thickening grows inwards and, as its surface increases, its walls become gradually thinner. Rudiments of the ptilinooesophageal muscle are obvious even immediately after eversion of the head; other muscles do not appear until the fourth day after pupation. In the newly emerged fly the ptilinum is continuous with the integument of the frons, genae, and vertex. Two unpaired and one pair of retractor muscles are inserted on the ptilinum; six other muscles appear to be accessory in connexion with pulsation of the head during emergence. By rhythmic expansion and contraction of the ptilinum the puparium is ruptured and emergence of the fly assisted. After final retraction of the ptilinum into the head-cavity, and hardening of the surrounding head integument, no more use is made of the organ. During the adult life of the fly the ptilinal integument is reduced to a layer of spinules. Before two days have elapsed after eclosion practically all the ptilinal and accessory muscles have disappeared. Their disappearance does not appear to be due to phagocytic activity. From histological evidence the cause and mechanism of muscle degeneration cannot be ascertained. A possible method of origin of the ptilinum from a membranous area above the antennae is suggested. Eristalis, without ptilinum, is compared with Calliphora. From the evidence brought forward it is suggested that the Aschiza and Schizophora represent two independent lines of development.
The Histology, Cytology, and Embryology of Sponges
Authors: Webb D. A.
Published: April 2021

The classical investigations which form the foundation of our knowledge of the minute structure of sponges were mainly carried out in the latter half of the nineteenth century by Haeckel, Schulze, Sollas, Poléjaeff, Topsent, Minchin, Maas, and other workers. In the earlier years of this century while many papers were published dealing with taxonomy, skeletal structure, physiology and descriptions of new species, the study of the soft parts was somewhat neglected, though the work of Minchin forms an important exception. More recently, however, a revival of interest in these aspects, assisted by modern fixing and staining methods, has resulted in a considerable increase in our knowledge. It is the aim of this paper to give a résumé of the literature published during the last twenty year which deals with those aspects of sponges indicated in the title. 1914 has been chosen as the beginning of the period since all previous references are available in Vosmaer’s bibliography.1
On the Ciliary Mechanisms and Interrelationships of Lamellibranchs: PART I: New Observations on Sorting Mechanisms
Authors: Atkins Daphne
Published: April 2021

The gills of Solen marginatus, Ensis siliqua, and Ensis arcuatus are synaptorhabdic or eulamellibranchiate, and the lamellae plicate and heterorhabdic. The latero-frontal cilia are large; there are in addition small subsidiary laterofrontal cilia. The frontal cilia on the filaments forming the bottom of the plical grooves are fine and beat dorsally. In the two species of Ensis the frontal cilia on the filaments forming the sides and apices of the plicae are arranged in two tracts with the effective beat in opposite directions; in Solen marginatus in three tracts, a median one of coarse cilia beating ventrally and two outer ones of fine cilia continuously beating dorsally.

In both genera the movement of particles in the plical grooves is dorsalward; on the crests mainly ventralward; on the sides of the plicae ventral or dorsal according apparently to their type and number.

Along the marginal grooves of the demibranchs, between the bases of the two demibranchs of a gill, and along the dorsal edges of all the ascending lamellae, currents are towards the mouth.

The gills of Cultellus pellucidus are synaptorhabdic or eulamelhbranchiate, and the lamellae flat and homorhabdic. The ventral edge of the outer demibranch is ungrooved. On the frontal surfaces of the filaments of both lamellae of the inner and the ascending lamella of the outer demibranch there are, in addition to fine cilia, a tract of long, coarse ones which beat ventrally. The fine frontal cilia, which alone are present on the descending lamella of the outer demibranch, beat dorsally, and, so far as could be ascertained, the tracts of fine cilia on the other three lamellae of the gill also beat dorsally.

The obvious frontal currents are toward the ventral edge on both lamellae of the inner and on the ascending lamella of the outer demibranch, and dorsalward on the descending lamella of the outer demibranch. Along the marginal groove of the inner demibranch, between the bases of the two demibranchs of a gill, and along the dorsal edges of all the ascending lamellae, currents are towards the mouth.
Description of a New Genus of Diatomaceæ, and observations on the costæ of Pinnularia Peregrina
Authors: Kitton Frederic
Published: April 2021

A Valued correspondent has informed me that the form described in the Synopsis as Gomphonema Fibula is not a Gomphonema, but must be considered a new genus.