bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Biological Relationship between Septobasidium retiforme (B. & C.) Pat. and Aspidiotus Osborni New. and Ckll
Authors: Couch John N. 
Published: April 2021

ABSTRACT
S. retiforme (B. and C.) Pat. is associated with A. Osborni New. and Ckll. The fungus insect relationship is perennial, depending only upon the life of the tree. The fungus furnishes a home and protection for the scale insects. The scale insects suck the juices of the host plant, grow, and finally reproduce their young in vast numbers. These young may pursue one of three courses: (1) they may settle down beneath the same fungus under which they were born and repeat the cycle; or (2) they may crawl out to other fungus-insect colonies; or (3) they may crawl out and settle down on the clean bark. The latter insects are entirely responsible for the dissemination of the fungus. Certain young become infected soon after they are born. The manner of infection; the development of the fungus within the bodies of the young; and the final growth and establishment of new fungus-insect colonies are described. Parasitized insects are proportionately much more abundant during the late spring and summer months than during the fall and winter months. The type of parasitism is of a highly specialized nature. The fungus enters the circulatory system of the living insects and there develops numerous coils which absorb food from the insect. A number of the insects are finally killed and used up by the fungus; others, though infected, may digest the fungal haustoria and survive to reproduce, and some are free from any infection. Such a conjoint relationship beneficial both to the fungus and to the scale insects is obviously symbiotic.
A New Protozoon, Hyperidion thalassemae n. gen., n. sp., from the intestine of Thalassema neptuni Gärtner
Authors: Mackinnon D. L. , Ray H. N. 
Published: April 2021

ABSTRACT
In the spring of 1930 we found in the intestine of the echiurid worm Thalassema neptuni at Plymouth a peculiar protozoan organism which seems worthy of some description. During the summer term we had additional specimens of the worm sent to us from Plymouth and kept them under observation in the laboratory, but we learnt little more about the parasite than we had already gathered from our earlier observations. We examined, in all, 145 worms: 20 per cent, of those dredged in the sound were infected, but we never found the parasite in those taken between tide-marks.
The Development of the Skull of Scyllium (Scyliorhinus) canícula L
Authors: Beer G. R. de 
Published: April 2021

ABSTRACT
The development of the skull of Scyllium canicula has been studied from the first appearance of cartilage, through thirteen stages, up to the point at which the main features of the adult skull have been acquired. The parachordals are the first elements to chondrify, and evidence is presented confirming Goodrich’s observations con- cerning the visible traces of metameric segmentation of the metotic region of the parachordal. The auditory capsule chondrifies from the first in con- tinuity with the parachordal, to which it is attached by the anterior basicapsular commissure. The polar cartilages have not been found separate, but they appear as nodules of cartilage attached to the under surface of the anterior ends of the parachordals. The orbital cartilage becomes attached to the parachordal by means of the pila antotica, and to the trabecula at the base of the lamina orbitonasalis by means of the preoptic root. The hind wall of the pituitary fossa is formed in a complex manner, from a postpituitary commissure between the polar cartilages, and a pair of inwardly directed processes from the foremost ends of the parachordals forming the dorsum sellae. There is also a precarotid commissure, enclosing the carotid arteries in a foramen between itself and the postpituitary commissure. The basicranial fenestra has been demonstrated. Arguments are given for rejecting Allis’s view that the so-called basicranial fenestrae throughout the craniates are not homologous. Attention is called to the vacuity in the median wall of the auditory capsule through which the posterior canal bulges, and to the fact that this vacuity is not to be confused with the fora- men endolymphaticum. The relations of the glossopharyngeal nerve are described, and it is shown that its apparent passage through the cavity of the auditory capsule is to be ascribed to the fact that the lamina hypotica of the parachordal acts as a false floor to the auditory capsule, the true floor of which is in this region un- chondrified. The problem of the relations of the jaws to the brain-case is reviewed in the light of recent investigations, and a reasoned classification is attempted. It is noticed that chondrification is delayed in embryonic material collected from Naples, as compared with material of similar size and degree of development obtained from Plymouth.
The Activities of the Tube Feet of Asterias rubens L.: I. The Mechanics of Movement and of Posture
Authors: Smith J. E. 
Published: April 2021

ABSTRACT
1. An account is given of the muscular anatomy of the foot and ampulla of Asterias rubens. An intrinsic musculature of the sucker figured by Cuénot (1891) and Chadwick (1923) is shown not to be present; on the other hand, postural muscles responsible for orientating the podium, levator fibres which ‘cup’ the sucker, and radial fibres which flatten it are described and figured for the first time.
2. The role of the different muscle systems, the collagen connective tissue, and the fluid of the hydrocoel in protracting and retracting the foot, and in effecting the attachment and detachment of the sucker, is discussed.
3. Evidence is presented, to show that postural pointing of the foot is brought about by the contraction of a ring of muscles encircling the base of the podium. The orienting muscles are functionally, but not anatomically, distinct from the longitudinal fibres of the retractor sheath.
4. The ambulatory step is shown to comprise a series of linked phases of static posture and of movement. Each phase is characterized by the contraction of one member of each of the two opposing pairs of muscles engaged in the development of the step. The two pairs of muscles are (1) the anterior and posterior orienting fibres, and (2) the protractors and retractors of the foot. In its ideal form the step comprises four phases of static posture alternating with four movements. Each movement is ushered in by a reversal of the contraction-relaxation relationships of one of the two pairs of opposing muscle systems. Four such changes are possible and they occur in a sequence that ensures the orderly succession of the four movements of protraction, swing back, retraction, and swing forward, of which movements the idealized stepping cycle is composed.
5. The actual locomotory step departs from the ideal form in two respects: (1) it is liable to become disrupted by a delay in the initiation of the protraction or of the backswing movement, and (2) withdrawal of the podium occurs simultaneously with its re-orientation in the forward direction. It is pointed out that these variations are explicable on the assumption that, in the two series of opposing muscle pairs, the retractor fibres are more readily excited to contract than are their antagonists, and the anterior postural muscles than the posterior postural fibres.
The Nephridia of Geonemertes dendyi
Authors: Pantin C. F. A. 
Published: April 2021

ABSTRACT
Geonemertes Dendyi (Dakin) is a terrestrial nemertine. The genus has a predominantly Australian distribution, but in recent years this species has been recorded from the western parts of England and Wales (Waterston and Quick, 1937; Pantin, 1944). In this genus the nephridial system is highly developed, and its structure in several species has been described by Hett (1924), Coe (1929), and others. Stammer (1934) mentioned the existence of a nephridial system in G. dendyi but did not describe it. The present work arose from a study of this species collected in South Devon, in all stages from the newly hatched young to the adult. The nephridial system proves to be at least as highly developed in this as in other species, and there are points of some interest regarding its function.
The Behaviour of Mammalian Skin Epithelium under Strictly Anaerobic Conditions
Authors: Medawar P. B. 
Published: April 2021

ABSTRACT
In the course of some experiments on the nature of skin transplantation immunity, it became necessary to find out for how long (if at all) mammalian skin epithelium can survive in the total absence of atmospheric oxygen. The results of the investigation are summarized here in the hope that they may be useful to other students of tissue behaviour.
Further Observations on the Glomerular Root of the Vertebrate Kidney
Authors: McManus J. F. A. 
Published: April 2021

ABSTRACT
There is a gap in the reticulin at the glomerular root of the mammalian kidney. This gap leaves the macular segment of the second convoluted tubule in intimate contact with the arteriolar cells, which in this region contain granules consisting of or containing masked lipoid. Methods are given for the demonstration of these granules in the mouse, rabbit, and man.
The cells of the macula densa of the mouse are poor in lipoid, and there is thus a striking contrast both with the adjoining cells of the same tubule and with the adjacent arteriolar cells.
The Golgi Material of the Neurones of the Central Nervous System of Sheep Infected with Louping-ill
Authors: Gresson R. A. R. , Zlotnik I. 
Published: April 2021

ABSTRACT
1. The Golgi material of the pyramidal cells of the cerebral cortex, the Purkinje cells of the cerebellum, and the multipolar cells of the medulla oblongata and ventral horns of the spinal cord of the sheep is present as filaments and as irregularly shaped bodies. In some of the cells, particularly in the lamb (Sheep V), the Golgi material has the appearance of a network. As it is frequently present as separate bodies it is suggested that it may always consist of discrete Golgi elements which are sometimes situated in close proximity or in contact with one another. Filamentous Golgi elements are present in the basal part of the cell processes.
2. An examination of neurones from the corresponding regions of the central nervous system of sheep infected experimentally with louping-ill showed that the Golgi material undergoes changes consequent upon the invasion of the cells by the virus. The Golgi material undergoes hypertrophy, and at the same time there is a reduction in the number of filamentous Golgi elements and a reduction in the amount of Golgi substance present in the cell processes. These changes are followed by fragmentation. All the neurones of a particular region are not affected equally at the same time. The Golgi material of the Purkinje cells tends to form groups in the cytoplasm prior to fragmentation. In the multipolar cells of the medulla oblongata the hypertrophy of the Golgi material is not as great as in the other regions of the central nervous system. The Golgi material of the motor nerve-cells of the ventral horns of the spinal cord undergoes considerable hypertrophy which is followed by a grouping of the Golgi elements and fragmentation.
Amoeba kerrii (n. sp.): Morphology, Cytology, and Life-History
Authors: Taylor Monica 
Published: April 2021

ABSTRACT
1. An amoeba characteristically blackish when viewed under the low power of a Greenough binocular in reflected light was discovered and isolated from macerating water weeds found in fresh-water pools on the shore near the Marine Biological Station of Keppel.
2. A study of its morphology revealed its relationship to Schaeffer’s genus Metachaos. For reasons given above, the name Amoeba has been retained for the genus and the specific name kerrii has been given in honour of Sir John Graham Kerr.
3. The life-history has been worked out by means of pure-line cultures.
4. The cyst measures about 9µ in diameter. The newly hatched amoebulae grow slowly and develop eventually into young adults which, because of the small size of their crystals and nutritive spheres, are much less dusky than the mature individuals first discovered. An average adult size in creeping is 504 by 576µ.
5. The nucleus, which divides by mitosis, has the same general build as that of A. discoides, A. proteus Y, A. lescherae. Immediately under the nuclear membrane is an achromatic network containing chromatin blocks and connected with a more or less centrally placed karyosome, the whole immersed in-nuclear sap. The nucleus assumes varying shapes as it is rolled about by the streaming endoplasm.
6. Morula-like spheres (= the fission-spheres) give rise to two daughter amoebae by cleavage along a meridional central plane. Fission is confined to young adults.
7. A fission cycle is succeeded by a reproductive cycle. Any mature amoeba can give rise to encysted young which are formed by the action of chromidia escaping from the nucleus. The cyst-wall is single. Hundreds of encysted amoebulae may be formed from one mature amoeba. No sexual stages occur.
The Developmental Cycle of Botrylloides
Authors: Berrill N. J. 
Published: April 2021

ABSTRACT
Of the many studies made on ascidians in the past, few have included the organism in its entirety. The present account is of the whole developmental cycle of an organism exhibiting exquisite timing in its four-dimensional relationships, with an interpretation of a colonial organism as the result of a few interacting processes. A comparison of Botrylloides with Botryllus affords some analysis of the nature of differences of generic magnitude, as modifications of several basic activities.
Some Observations upon the Golgi Elements of the Anterior Pituitary Cells of Normal and Stilboestrol-treated Male Rats, using the Sudan Black Technique
Authors: Foster C. L. 
Published: April 2021

ABSTRACT
It was found possible to demonstrate the Golgi zones of the cells of the anterior pituitary (pars distalis) of the rat with Sudan black. The position and general morphology of the Golgi bodies closely resembled that revealed by the standard osmium tetroxide techniques. The Golgi zone was generally found to contain three sorts of element: (?) diffuse sudanophil material in which were embedded: (b) clear vacuoles and (c) strongly sudanophil bodies. The latter were often associated with the surfaces of the vacuoles, when they were in the form of (1) crescentic caps, (2) partial or complete rims of apparently uniform thickness, or (3) small granules. Sometimes the strongly sudanophil bodies were granular and unassociated with vacuoles; there were also vacuoles with no demonstrable lipoid material in association with their surfaces. The effect of stilboestrol was to cause hypertrophy of the Golgi zones and this was associated with (a) an increase in volume of the region of diffuse lipoids, (b) an increase in vacuolation, and (c) a rather more variable increase in the amount of strongly sudanophil material. These changes would appear to indicate a state of heightened secretory activity. The strong affinity of the Golgi area for sudan black suggests that it consists, at any rate in part, of lipoids.
A Comparative Histological Study of Haemosiderin in the Uteri of Mice of Cancerous and Non-cancerous Strains
Authors: Jones Vera E. 
Published: April 2021

ABSTRACT
In mice, haemosiderin is formed in the wall of the uterus from the blood extravasated into the tissues when the placenta breaks away at parturition. The pigment is formed, probably exclusively, within the phagocytes, and forms a mass in the mesenteric wall of the uterus. In mice of the cancerous strain used in this study (R III strain of Dobrovolskaia-Lavadskaia) the haemosiderin is formed more slowly and is disposed of much more slowly than in the non-cancerous strains examined. Phagocytic inefficiency in the cancerous strain is suggested and its possible connexion with susceptibility to cancer is discussed.
Some Applications of Phase-contrast Microscopy
Authors: Barer Robert 
Published: April 2021

ABSTRACT
Some extensions of the simple theory of phase-contrast microscopy are considered. It is emphasized that transparency, rather than thickness, is the limiting factor for the successful employment of the method. Certain transparent insect larvae (Chaoborus, Chironomus) can be observed in the living state by phase-contrast illumination.
The statement that the method is of no value for the examination of fixed and stained sections is based on consideration of an ideal physical case. In practice the method may be a valuable adjunct to routine examination of such material. Examples are given of the application of phase-contrast microscopy to normal and pathological stained sections.
Nervous Structure of the Spinal Cord of the Young Larval Brook-Lamprey
Authors: Whiting H. P. 
Published: April 2021

ABSTRACT
It is intended to describe here the spinal cord of recently hatched ammocoetes of Lampetra planeri (Bloch). Particular attention will be given to those neurons which may be involved in the somatic sensori-motor arc. It is hoped to base upon this description a subsequent account of the embryo and young ammocoete, which will deal with the successive stages of nervous structure and their relation to the successive patterns of behaviour.
Phosphatase Activity of Drosophila Salivary Glands
Authors: Doyle W. L. 
Published: April 2021

ABSTRACT
The presence of alkaline phosphatase in chromosomes has been demonstrated by means of histochemical staining methods (Danielli, 1946; Krugelis, 1942, 1946). These studies indicated the effects of various fixatives and substrates on the subsequent staining reactions. The present study presents certain quantitative aspects of the effects of acetone, alcohol, and pH on the phosphatase activity of whole salivary glands of Drosophila.
A Further Note on Nile Blue
Authors: Cain A. J. 
Published: April 2021

ABSTRACT
In a previous paper (Cain, 1947) it was shown that nile blue can be used to distinguish between acidic and non-acidic lipoids, and that lecithin stained very deep blue with a 1 per cent, solution, while oleic acid was only faintly coloured. Since lecithin stains, it was suggested that other lipines might stain blue also and that the oleic acid used might be impure.
Ester Wax as a Medium for Embedding Tissue for the Histological Demonstration of Glycogen
Authors: Smyth J. D. , Hopkins C. A. 
Published: April 2021

ABSTRACT
The effect of paraffin wax embedding on the lability of glycogen in sections has been tested using as material (a) plerocercoid larvae of Ligula intestinalis’, (b) rabbit liver. It was found that glycogen in tissues was very impermeable to wax, and where large masses of glycogen occur prolonged embedding is essential. Improperly embedded material lost glycogen easily; it was concluded that this loss takes place during the processes of cutting and flattening sections. The effect of prolonged embedding was to make tissue hard and refractive. This difficulty was overcome by embedding in Steedman’s ester wax. Ester wax blocks allowed thin sections of very hard material to be cut with ease. Ester wax sections brought down to water did not lose glycogen even after standing in water for 7 days. It is emphasized that glycogen exists in two forms: an insoluble desmo-form and a soluble lyo-form. It is suggested that the latter does not dissolve from sections in water because its highly branched molecule is held by the coagulated protein network.
A New Single-control Micromanipulator
Authors: Barer Robert , Saunders-Singer A. E. 
Published: April 2021

ABSTRACT
New developments in microscopy and electrophysiology have brought a renewal of interest in methods of micromanipulation.
A number of features desirable in the design of a micromanipulator is discussed.
A new micromanipulator is described. Its outstanding features are (1) single control; (2) massive construction with freedom from vibration; (3) freedom from play; (4) continuous variability of sensitivity; (5) limitation of range of movement to the field of view; (6) rapid low-power centring; (7) unusual robustness combined with delicacy of movement achieved without any high-precision methods. The performance of the instrument is adequate for high-power cytological work and for microdissection by phase-contrast illumination.
Further Remarks on the Golgi Element
Authors: Baker John R. 
Published: April 2021

ABSTRACT
The Golgi element has been reinvestigated in the same kinds of cells as were the subject of the author’s 1944 paper. Two new methods have been used, namely, phase-contrast microscopy and an improved form of the sudan black technique, in which the tissues are postchromed at 60° C. The Golgi element consists of separate bodies, spheroid in shape. These Golgi bodies may be simple (i.e. non-vacuolate), or may contain one or more vacuoles. The material of the simple Golgi body and of the externum of the vacuolate body is a lipoid that in some cases can be shown to contain lipine. The secretion-product of the Golgi body originates in the vacuole. The opinion as to the structural plan of the Golgi element set out in the earlier paper has been confirmed in the main. There are, however, two exceptions to this: The vacuole in the Golgi body does not invariably colour with neutral red, and this dye occasionally causes the appearance of vacuoles not present before, both within the Golgi region and in other parts of the cytoplasm. ‘Diffuse lipoid’ is not a characteristic feature of the Golgi element.
Aldehydes in relation to Absorption of Fat from the Intestine and Metabolism of Fat in the Liver
Authors: Danielli J. F. 
Published: April 2021

ABSTRACT
During the absorption of fatty acids or of fat from the intestine of mice and rats, no intervention of long-chain aldehydes occurs. When fat is being metabolized or synthesized in the liver of mice and rats aldehydes are prominent. Each fat droplet being metabolized is sur- rounded by a spherical shell containing aldehyde and basiphilic material. The results indicate that long-chain aldehydes or their derivatives are essential intermediates in the metabolism of fatty acids, and suggest that the acetals of these aldehydes are intermediates in the synthesis of glycerides and phospholipines, &c.
A Simple Method for Phase-contrast Microscopy: Improvements in Technique
Authors: Baker John R. , Kempson D. A. , Brunet P. C. J. 
Published: April 2021

ABSTRACT
If the condenser of a microscope is first set in its so-called ‘critical’ position and then gradually lowered, the real image of the source sf light will be brought down from the plane of the diaphragm of the eyepiece till it reaches a position just behind (above) the back focal plane of the objective. If a piece of black paper, from which a ring-shaped strip has been cut away, is held immediately in front of the source of light, a bright image of the annulus can easily be thrown just behind the back focal plane of the objective by lowering the condenser to the appropriate degree. If now a phase-plate, provided with an annulus, is placed in the same plane as the image of the illuminating annulus, and if the phase-plate annulus is of such dimensions that it coincides with this image, phase-contrast microscopy will have been achieved.
The Cell-Theory: a Restatement, History, and Critique Addendum to Part II
Authors: Baker John R. 
Published: April 2021

ABSTRACT
Since writing Part II of this series of papers (Baker, 1949), I have had the good fortune to find a figure, published by Roffredi in 1775, which shows nuclei in the eggs and embryos of a nematode. This figure antedates by fifty-five years Purkinje’s description of the germinal vesicle (1830) (or by fifty years, if we use the date of the private circulation of Purkinje’s memoir).