bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparative Study of Striated Muscle
Authors: Haswell William A. 
Published: April 2021

ABSTRACT
There are very many discrepancies between the statements which we find in the writings of various observers as to the distribution of striated muscular fibres in the various classes of Invertebrata. These discrepancies are due partly to defective methods of investigation and misinterpretation of the appearances observed, but partly also to the want of a distinct understanding as to what constitutes “striation “in muscle. Clearly our conception of striation in muscular fibres is derived originally from the study of the tissues of the voluntary muscles of Mammalia and the Frog, and the limb-muscles of Insects, since it was in these that the striation was first observed, and it is in these that the nature of striation has been invariably investigated. Now what are the essential characteristics of striated fibres in such instances ? They are five in number.
A striated muscular fibre in these cases consists of a bundle of narrower elements, the fibrils, which are capable by certain methods of treatment of being isolated from one another. The whole substance of the fibre is composed of two series of transverse segments, the anisotropous and isotropous series, differing in optical properties and affinity for certain dyes, which alternate with one another, the segments of the one series being doubly refracting and readily affected by haematoxylin or carmine (anisotropous segments) ; while those of the other set are singly refracting and are not readily stained (isotropous segments). Running transversely across the whole fibre in the middle of each singly refracting segment is a network or membrane, the transverse network, or Krause’s membrane. Running between the fibrils are a number of delicate threads, for the most part longitudinal in direction, constituting the longitudinal networks. Each fibre is, so far as known, formed originally from a single formative cell, the nucleus of which undergoes division, giving rise to a multinucleated protoplasmic body1 by modification of whose protoplasm the muscle substance and networks are formed.
Contributions to Animal Chromatology
Authors: Munn C. A. Mac 
Published: April 2021

ABSTRACT
The following observations, although they are not as complete as one might wish, may yet be found useful to those who take an interest in Animal Chromatology. The greater part of them is the result of a short visit to the Marine Biological Laboratory at Plymouth last year. Owing to my having been provided with only one spectroscope of small dispersion at Plymouth, I am unable to guarantee the accuracy of the measurements. The chemical laboratory there was not at that time yet fully equipped, so that I could not thoroughly examine the pigments, but the characters given below are sufficient to enable one to form an opinion as to their connexion with other pigments.
Note on the Transformation of Ciliated into Stratified Squamous Epithelium as a Result of the Application of Friction
Authors: Haycraft John Berry , Carlier E. W. 
Published: April 2021

ABSTRACT
In man, in the rabbit, and in some other animals, the trachea, as is well known, is built up of a series of cartilaginous rings, which are incomplete behind. Posteriorly, where the cartilage is wanting, involuntary muscular fibres are found. These are placed transversely, and form what is called the trachealis muscle, which is placed outside the cartilage. The mucous membrane forms a smooth cylindrical lining to the cartilaginous walls of the trachea, and is covered by ciliated epithelium. In the cat and the dog the rings of cartilage overlap posteriorly for a considerable distance, and the trachealis muscle, which is much developed in these animals, and placed outside the cartilage, evidently exerts a powerful action in varying the diameter of the tube.
Terminations of Nerves in the Nuclei of the Epithelial Cells of Tortoise-shell
Authors: Haycraft John Berry 
Published: April 2021

ABSTRACT
The land tortoise (Testudo græca), so commonly imported into England from the south of Europe, appears to be a very sluggish animal. This is not really the case, and its movements on a hot summer day are the reverse of phlegmatic. In this condition its carapace is sensitive to the slightest impact. If the carapace or plastron be very gently tapped, the nearest leg is alone withdrawn, a heavier tap causing a withdrawal of its whole body. We have here, therefore, a structure which is a true sensitive surface, and like the soft skin of a frog or of a man, it is brought into relationship with the central nervous system. Like the soft skin of other animals it may be mapped out into areas, from which the nerve-fibres passing to the spinal cord are all especially connected with outgoing motor nerves, so that the definite reflex movements of limbs as already described may come about.
Immunity Against Microbes
Authors: Ruffer M. Armand 
Published: April 2021

ABSTRACT
When examining the microscopic world actively growing in various infusions, we are often able, says Metschnikoff,1 “to follow with our eyes the struggle taking place between the representatives of the Flora and Fauna of microbes. Many unicellular animals, such as Amœbæ and other Rhizopoda, as well as flagellated and ciliated Infusoria, feed on various bacteria, devour them in great numbers, and take them into their protoplasm in order to extract from them the necessary nutritive material. Small Monads in the course of a few minutes take into their interior Leptothrix filaments ten times longer than they are themselves.” It is a very old observation that Amœbæ and other Protozoa seize dead particles, and, after extracting the nutritive material contained in these, reject the remainder.
On the Minute Structure of the Gills of Palæmonetes varians
Authors: Allen Edgar J. 
Published: April 2021

ABSTRACT
Kowalevsky1 states that when he injected Palsemon with a strong solution of litmus, two red stripes appeared on the axis of each gill, the effect being due to the colouring matter having been deposited in two solid strings of cells, which lie on both sides of the axis, near the channels through which the blood flows from the gill lamellæ to the heart (branchiocardiac canals). Professor Weldon drew my attention to this statement, and suggested that I should endeavour to work out the minute structure of the gills, of which no description, so far as I am aware, at present exists. My observations have been carried on chiefly upon Palæmonetes varians, as this form can be more readily obtained alive and kept in confinement in London.
On Teichmann’s Blood-Crystals
Authors: Hendry William 
Published: April 2021

ABSTRACT
Having an impression that the nature of Teichmann’s blood-crystals, supposed to be that of pure hæmatine or of the colouring matter of blood, and hence termed hematin-crystals, may not be so generally understood as the subject seems to merit; believing also that but very few individuals amongst those whom their production may chiefly interest have hitherto undertaken manipulations with respect to them, and the subject at large possessing a general microscopical value, as well as being of some interest in medical jurisprudence, I have deemed it worth while to awaken the attention of your readers to it, with the earnest hope of inducing some to undertake enlarged experiments, and of eliciting additional facts, which may tend to still greater utility.
On “Contractility” as distinguished from purely Vital Movements
Authors: Beale Lionel S. 
Published: April 2021

ABSTRACT
There are probably few actions more different than the contraction of a muscle or the vibration of cilia, and the movements which occur in a living Amoeba, in a living mucus-corpuscle, or young epithelial cell; but it is generally considered that all these movements depend on a property which has long been known as contractility. And yet one would hardly conceive it possible that even a casual observer, who had attentively watched ciliary or muscular action, and the movements of an Amoeba, for example, would fail to discern a remarkable difference in the movements he observed, although he might be quite unable to define in what essential points the movements differed. Not only are there essential differences between these (at least) two classes of movements, both of which occur in all the higher organisms, but I think it can be shown that the matter which is the seat of the observed motion is not of the same nature in each case. I have endeavoured to prove that the so-called moving matter (sarcode) of an Amœba or of a mucus-corpuscle, white blood or pus-corpuscle, corresponds to, or is homologous with, the so-called “nucleus,” and not with contractile material of muscle. The moving matter of the former and the so-called “nucleus “of the latter correspond, and I have termed this living or germinal matter, while the latter I. consider to be formed matter, and therefore no longer the seat of vital changes.
The Life-History of Nucula delphinodonta (Mighels)
Authors: Drew Gilman A. 
Published: April 2021

ABSTRACT
The material upon which these observations were made was secured at Casco Bay, Maine, during the summers of 1897 and 1898. Nucula delphinodonta is a small form, seldom growing to be more than 4 mm. in length, and as it lives below low-tide mark it is not very well known by collectors. By using a sufficiently fine dredge, however, unlimited numbers of adult and young specimens may be procured. Individuals may be found living under very different conditions; in inlets and protected places, and exposed to the open sea, and from near low-tide mark to a depth of several fathoms. The principal habitat, however, is in the shallow inlets and near the heads of sounds, where the bottom is composed of fine mud, mixed with some sand, broken shells, and decaying vegetable matter. Individuals are most numerous just outside of the eel grass which skirts the shore where the bottom is of this character, in water which at low tide is from one to three fathoms deep. The mud in which they live is much like that inhabited by Yoldia limatula, except that it is not so free from shore débris. Although some specimens may be obtained where Yoldia is most abundant, they are generally more numerous somewhat nearer the shore, and they may be very numerous at considerable distances from places where Yoldia is known to thrive.
The Crystalline Style of Lamellibranchia
Authors: Mitra S. B. 
Published: April 2021

ABSTRACT
Four hypotheses have been framed with regard to what the crystalline style of the Lamellibranchia is and does: (1) Gegenbaur thought it was a secretion from the enteric epithelium (‘Elements of Comparative Anatomy,; English translation, p. 359). (2) Balfour suggested that it was to be considered as a rudiment of the radular sac of the Glossophora (see Professor Lankester’s article on “Mollusca,” in the ‘Encyclopædia Britannica/ninth edition, p. 685). (3) Claus regarded it as an excretion of the enteric epithelium. (4) Sedgwick thinks it is to be regarded as a “reserve of nutriment” (‘Student’s Text-book of Zoology,; vol. i, p. 335). We may say at the outset that of all the hypotheses Gegenbaur’s was the nearest to the truth, for it is in reality a secretion, a digestive ferment whose function it is to digest starch, i. e. to convert starch into a reducible sugar.
On the Development of Sagitta; with Notes on the Anatomy of the Adult
Authors: Doncaster L. 
Published: April 2021

ABSTRACT
The development of the Chætognatha was first investigated by Gegenbaur, but the earliest full account was given by Kowalevsky in 1871 (1). He described the gastrulation, the formation of the archenteric pouches, and the subsequent stages up to the hatching of the young Sagitta. Bütschli studied another species taken off the coast of Norway in 1873 (2), and found considerable difference between this species and that which Kowalevsky had described. The most important new facts which he added were, firstly, the formation of separate anterior cavities of the cœlom, separated off in the earlier stages of the embryo from the archenteric pouches ; and secondly, the very early separation of the cells which remain unaltered during the whole embryonic development, and which ultimately give rise to the male and female generative organs.
On Peripatus guianensis (sp. nov.)
Authors: Evans Richard 
Published: April 2021

ABSTRACT
To add another species to the already somewhat large number of the New World members of the family Peripatidæ will probably seem to many zoologists to be unwarranted presumption, for within the last few years the number of species from this part of the world has been more than doubled—a result, to some extent, of redescribing old material rather than of discovering new forms. However, the species under consideration in the present paper cannot be identified with any of the already known ones; and whatever view we choose to adopt regarding the validity of some of the species which have been made, I am of opinion that no one will doubt,after perusal of the facts which will be recorded in the coming pages, that Peripatus guianensis is a new species.
On the Development of Flagellated Organisms (Trypanosomes) from the Spleen Protozoic Parasites of Cachexial Fevers and Kala-Azar
Authors: Rogers Leonard 
Published: April 2021

ABSTRACT
The small oval parasites, known under the name of Leishman-Donovan bodies (although they appear to have been first found by D. D. Cunningham in Dehli boil) were described last year as occurring in the enlarged spleens of patients dying of chronic fever with marked cachexia by Leishmau, who considered them to be degenerate trypanosomes, because he found somewhat similar bodies form with a large and a small chromatine mass in the spleens of rats which had died forty-eight hours before of trypanosomiasis due to the organisms of tsetse fly disease. Donovan, working in Madras, found similar bodies in blood obtained fresh from patients suffering from this fever, thus proving that those seen by Leishman were not degenerate trypanosomes, and Laveran, after examining Donovan’s specimens, came to the conclusion that the parasite was apiroplasma. Ross, Nuttall, and Manson have all dissented from this view, and regard the organism as probably belonging to a new genus. Christophers suggests that it is a microsporidium.1
Some Facts in the Later Development of the Frog, Rana temporaria: Part I.—The Segments of the Occipital Region of the Skull
Authors: Elliot Agnes I. M. 
Published: April 2021

ABSTRACT
The question of the segmentation of the vertebrate head is one which for a long time has attracted the attention of many investigators. With regard to the segmentation of the anterior and middle parts of the head the facts are conflicting, and opinions differ; but, with regard to the postotic portion, there is a converging mass of evidence, drawn from the neural, muscular, and skeletal tissues, that a varying number of segments serially homologous with the trunk segments have been drawn into the head. Besides this there is also evidence that in this region, in some groups at all events, a certain number of segments have altogether dropped out, and are not now represented by any rudiments, even in the embryo.
Peripatus ceramensis, n. sp
Authors: Muir F. , Kershew J. C. 
Published: April 2021

ABSTRACT
Female.—Antennæ dark grey, the articulations thinly ringed with ochreous. Eyes shiny black. Oral papillæ pale ochreous at the base, pale grey on tips, and dotted there with black. Head and anterior part of body to about the second pair of legs rather pale rust-colour, irrorated with black; there is in some specimens an ochreous marking on the dorsal median line of the head. Rest of body dark slaty-grey, irregularly spotted with small sub-circular rust-coloured spots, most of them centred with a black dot (the spots are the bases of papillæ, the black dots the bristles at the summits). These spots extend to near the head, but arc there smaller and paler. There is a narrow median dorsal line of very dark grey, becoming narrower, paler, and almost obsolete near the head, but it continues fairly distinct to the anus. This line, under the microscope, is seen to be divided longitudinally by an exceedingly fine light line. Underside wholly grey, lighter than the upperside, and irregularly spotted with pale ochreous, chiefly on each side of the median line. Round the mouth is pale ochreous. Legs on the inside concolourous with the underside ; on the outside concolourous with the upperside, and with a few pale rusty spots, chiefly near the base. Just around the anus the skin and papillæ are ochreous or rusty. The spiniferous pads on the legs are pale ochreous. Between each pair of legs, on the median ventral line, is a rather large light ochreous spot. Papillæ round genital opening whitish.
Observations on Trypanoplasma congeri
Authors: Martin C. H. 
Published: April 2021

ABSTRACT
In the ‘Zoologischer Anzeiger,’ Bd. xxxv, Nos. 14 and 15, Mr. Elmhirst and I published a short note on a trypanoplasma parasitic in the stomach of the conger eel (Conger niger). Up to the present, as far as I am. aware, no satisfactory account has been given of the division of any trypanoplasma, and the only point in connection with this process, on which previous workers have been unanimous, seems to be the extreme rarity of dividing forms. By what I must now regard as rather a fortunate accident, the second conger which I chanced to examine was so heavily infected that frequently two dividing forms have been found in the same field. As such infections, however, seem extremely rare, I have decided to publish my observations on the division of the active form of Try panoplasm a congeri at once, reserving the notes we have at present made on the changes into the resting form for a later paper. In the later paper we hope also to deal more fully with the general literature of the group. I shall only mention in this paper the previous accounts of intestinal trypanoplasma, and, in a later section of the paper, I shall refer to the descriptions of division given for this genus by Keysselitz and Friedrich. The first description of an intestinal trypanoplasma was given by Léger in 1905 for a form, Trypanoplasma. intestinalis, which be found in the stomach of Box boops.
Notes on a Deep-sea Echiuroid, Acantho-hamingia shiplei (n. g. et n. sp.), with Remarks on the Species Hamingia ijimai, Ikeda.
Authors: Ikeda Iwaji 
Published: April 2021

ABSTRACT
In July, 1909, I obtained au Echiuroid animal through the kindness of Mr. Aoki, of the Marine Biological Station at Misaki, Japan. As at that time the date of my departure from Japan was near at hand I was compelled to bring with me the specimen, which remained untouched until the end of October, when I entered the Zoological Laboratory of the University of Cambridge. After some weeks’ work in that laboratory I discovered that this single specimen was a very curious and undescribed species belonging to the Bonellidæ, and apparently to the genus Hamingia. Doubt was, however, thrown upon relationship of the new form to Hamingia by two remarkable features, the presence (i) of the abnormally numerous ventral hooks and (ii) of the skin-papillæ. The absence of the two structures just mentioned represents the most essential generic characteristics of Hamingia, distinguishing the genus from the rest of the Bonellidæ, Boneilia and Protobonellia.1 Seeing many close relationships between the present species and Hamingia ijimai,2 both in its general “facies “and its anatomy, I suspected that the type-specimen of H. ijimai might possess the two structures mentioned above, and I asked Mr. S. Takahashi, my colleague in the College of Hiroshima, to re-examine the type-specimen. His reply was that H. ijimai has hooks similar in nature to those of the present species, but no skin-papillæ at all. Thus informed, I have decided to propose the new genus Acanthohamingia for the reception of both the present species and that which I formerly described as H amingia ijimai. The question of classification will be more fully discussed later. The following contribution, though brief and incomplete in many points, is produced with the hope of adding something to our present knowledge of the group of Bonellidæ. Before going further, I wish to express my deep gratitude to Professor J. Stanley Gardiner, F.R.S., and Mr. A. E. Shipley, F.R.S., through whose great kindness and generosity I have been enabled to produce the present study, being supplied with every necessary convenience of the laboratory. I also feel greatly indebted to Mr. S. Takahashi for his kindness in supplying me with the prompt information for which I troubled him.
On Cristispira veneris nov. spec., and the Affinities and Classification of Spirochæts
Authors: Dobell C.Clifford 
Published: April 2021

ABSTRACT
During the last few years many memoirs have made their appearance in connection with the remarkable group of Protista which may be conveniently collected under the common name “Spirochæts.” Of these organisms the most divergent descriptions have been given, and consequently the most divergent views have been held regarding their affinities with other organisms. Many workers consider that the Spirochæts are allied to the flagellate Protozoa; many consider that their proper systematic position is among the Bacteria. As I have devoted a considerable amount of study to both these groups—as regards their cytology and lifehistories—I have naturally been anxious to extend my studies to the Spirochæts. The present paper represents a part of the researches which I have made upon these organisms, with the conclusions derived from them. I may state at the outset that my own observations have led me to believe that the Spirochæts are really neither Protozoa nor Bacteria, but a group of Protista which—for the present—must be held to stand apart.
Further Observations on the Cæcal Parasites of Fowls, with Some Reference to the Rectal Fauna of other Vertebrates PART I
Authors: Martin C. H. , Hobertson Muriel 
Published: April 2021

ABSTRACT
During the last two years we have been engaged in some work on the cæcal parasites of the fowl, and although we do not feel that our work is complete, we have decided to publish some of the results we have obtained.
Cytological Observations on the Early Stages of Segmentation of Echinus Hybrids
Authors: Doncaster L. , Gray J. 
Published: April 2021

ABSTRACT
The material on which the greater part of the observations here described was made was handed over to us by Messrs. Shearer, De Morgan and Fuchs, and was collected by them while carrying out experiments on the characters of the phitei in hybrids between the British species of Echinus. A preliminary account of their results has been published,1 and their fuller paper appears concurrently with this. In view of the fact that in some of the hybrids the plutei, whichever way the cross was made, were essentially of the maternal type, it was clearly of interest to determine whether an elimination of paternal chromosomes takes place comparable with that described by Baltzer,2 who has found that in the early stages of hybrids between different Echinoid genera, paternal chromosomes are eliminated in those cases in which the phitei are of the maternal type. The species used in the present experiments were Echinus esculentus, E. acutus, and E. miliaris, the three species of Echinus found at Plymouth, where the experiments were made. The material obtained in 191.1 consisted of segmenting eggs of these three species, and of the hybrids eseulentus ♀ × acutus ♂, acutus ♀ × esculentus ♂, and acutus ♀ × milaris ♂, preserved at intervals of from half an hour to five hours after fertilisation.