bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Observations on the Ecological Variation and Development of the Cruciate Zigzag Camouflage Device of Argiope pulchella (Thor.).
Authors: Marson J. E. 
Published: August 2010

Summary.The cruciate zigzag of Argiope pulchella (Thor.) is not specific, considerable variation in form and size occurring in different habitats. In any type of habitat, however, the type of device used is constant.The intensity of illumination seems to be the factor determining the size and completeness of the device, the device being more complete and larger with an increase in illumination.The density of the webbing used in the device and the distinctness of the zigzag formation are apparently controlled by two factors, the intensity of the illumination, and the speed at which the device is constructed. These two are, however, inter‐related as an increase in illumination, brings a corresponding increase in the speed at which the device is constructed. Increase in these two factors causes an increase in the density of the webbing used and a decrease in the distinctness of the zigzag formation.This variation with the intensity of the illumination is reasonable as the effectiveness of the cruciate zigzag as a camouflage device decreases with a decrease in the intensity of the illumination, becoming detrimental when the web is in a dark habitat. It would appear then that Natural Selection has not selected this species because of the cruciate zigzag in its web but because of the spider's ability to modify the device according to the habitat in which it spins its web.
A Note on the Female Reproductive Tract in the Tree Kangaroos (Dendrolagus)
Authors: Matthews L. Harrison 
Published: August 2010

Summary.The anatomy and histology of the female reproductive tract in Dendrolagus matschiei and D. ursinus are described and compared with the previous brief accounts of the anatomy in D. inustus.There is considerable variation in the degree of development of the lateral vaginae; this may be specific, but is more probably a function of age and sexual activity. The median sinus vaginalis extends caudally to the caudal junction of the lateral vaginae, and ends blindly in the tissue of the urinogenital strand ventral to that junction, and a little cranial to the urethral meatus. There is a short common vagina, and a comparatively long urinogenital canal. The uteri open into the upper ends of the lateral vaginae through conspicuous papillae on their dorsal walls. The ovaries are contained in peritoneal pouches formed in the ligamentum latum genitale, and the abundant fimbriae cover the mouths of the ovarian sacs thus formed. Histological examination of the various parts of the reproductive tract shows that the primitive circular muscular coat forms the greater part of the walls of the uteri and of the lower parts of the lateral vaginae, and that only in the sinus vaginalis do the longitudinal fibres form a complete coat in addition to that formed by the circular ones. The ovary shows a complete lack of interstitial tissue, but a large amount of luteal atresia. The structure of the follicle and of the corpus luteum atreticum is described, and the possible method of formation of the latter is discussed in the light of the studies of other workers.
Studies on the Biology of British Limpets.
Authors: Evans Ronald G. 
Published: August 2010

Summary.(1) The limpets of Cardigan Bay have been studied to provide records additional to those of Eslick (1940) for the Isle of Man and those of Fischer‐Piette (1935, 1938) for the Channel coasts, and to place the recognition of the three species on a clearer basis.(2) The nomenclature of the British species ofPatellais discussed, and it is decided to adhere, in the present study, to the system adopted by the Plymouth Marine Fauna (1931), and by Winckworth (1932),i. e.Patella vulgataL.Patella depressaPennant.Patella athleticaBean.This is related to the systems adopted by other workers.(3) From a detailed study of 400 limpets in the laboratory and an examination of several hundred specimens in the field, descriptions of the various conchological and anatomical characters have been made. The results are compared with those of Fischer‐Piette (1935, 1938) and of Eslick (1940), and it is established that the three species are quite distinct in Cardigan Bay. A key is suggested for identification, based on external characters.(4) The horizontal and vertical distributions between tide‐marks of the three species are described and are found to be quite distinct, although some overlapping occurs as among other intertidal forms.(5) It is shown that whilePatella vulgataandP. athleticaprobably occur all round the British Isles, there is no evidence thatP. depressaoccurs north of the Irish Sea and Bristol Channel. The statement of Fischer‐Piette (1935) that the three species merge in certain areas (e. g.the Isle of Wight) needs re‐investigation and an extensive and detailed analysis of the limpet populations at such localities. The resemblance between the dentition ofP. vulgataandP. depressais discussed, and the possibility of hybridization, in localities where both occur freely, is considered. It is shown that the similarity of the pluricuspids is much more marked in an area where both species are common (Cardigan Bay) than whereP. vulgataonly occurs (Isle of Man).Since the completion of the above work, I have examined several shells collected by Professor T. A. Stephenson at Salcombe, Looe, Bedruthan Steps, Watchet, Easdale, Staffa, Tantallan, and Charlestown. They are easily separated into the three distinct types here described, and differ in no significant way from the shells collected in Cardigan Bay.
Some Observations on the Eggs and Newly Hatched Embryos of Solpuga hostilis White (Arachnida).
Authors: Lawrence R. F. 
Published: August 2010

Summary.Certain features of the first larval stage of the South African Solifuge, Solpuga hostilis White, are described. The newly hatched larva is provided dorsally with a number of long and very stout brownish setae arranged serially in symmetrical pairs on the head, thoracic and abdominal regions of the body; in the larva which has just been released from the egg, they are folded in a characteristic manner, forming a pattern which is the same in all the larvae. The setae are quite different from the long delicate hairs and setae of the adult Solpuga, being very much longer and thicker in proportion to the body length.Before the rupture of the egg capsule, the eggs show a number of dark lines and markings, forming a pattern which is uniform in a series of 61 eggs. This pattern has nothing to do with the covering of the egg itself but is caused by the dark setae showing through the semi‐transparent capsule, some of them lying side by side to form fairly broad bands.The prominent larval setae of Solpuga hostilis are certainly not found in the newly hatched larva of Galeodes (araneoides and caspius), the only other Solifugae in which this stage of development has been described; such large setae are very unusual in the newly hatched stages of Arachnida and Myriopoda where the delicate and soft‐skinned larva on emerging from the egg is nearly always devoid of hairs, spines or other cuticular out‐growths.The claws of the appendages and the external appearance of the lateral organ are compared with these structures in Galeodes at the same stage of development.
The Morphology of the Ethmoidal Region of Sphenodon and Lizards
Authors: Pratt C. W. McE. 
Published: August 2010

Summary.

The nasal organs of Sphenodon and lizards are considerably modified by the mode of life, which in turn influences the form of the nasal capsule.
The anterior chamber functions as a filter in preventing foreign bodies from entering the respiratory tract. It is well marked in terrestrial forms that are specialized for a deserticolous existence, but it is very reduced in arboreal forms.
The lateral nasal gland passes its mucoid secretion into the anterior chamber, and serves to bind to the epithelium any small particles that have been inhaled. It is well developed in deserticolous and fossorial forms, but reduced in arboreal and semi‐aquatic lizards.
The olfactory chamber is well developed in terrestrial forms, but reduced in arboreal ones. Conchal formation is dependent upon orbital expansion.
Jacobson's organ is a specialization of ground‐living lizards, and is reduced in arboreal forms. Stimulating particles are deposited by the tongue onto the choanal fold. They are carried by means of ciliary currents into, and along a continuous stream of lachrymal fluid passing to the organ. Some lizards by the development of deeply forked tongues deposit the particles directly into the organ.
The definitive nasal capsule is formed by the fusion of two distinct morphological elements. There is a medial rostral process which belongs to the cranium, and consists of the nasal septum, dorsal plate, and sphenoethmoidal commissure. The lateral capsular element, which is a true sensory capsule, is divisible into parietotectal, paranasal, paraseptal, and ectochoanal cartilages.
The rostral elements arise earlier in the embryo than do the capsular elements, and are distinguished in the adult by the relations of the profundus nerve, which lies ventral to the rostral element and dorsal to the capsular element. The line of union is taken from the points of entry and exit of this nerve, and the position of certain fenestrae.
The fenestrae are due in the first place to weak development of the dorsal plate, and secondarily follow weak capsular development. In the case of fenestrae superior it follows weak parietotectal cartilage development, while fenestrae lateralis appears where there is marked conchal formation.
The dorsal plate forms most of the roof of the capsule, and with the spheno‐ethmoidal commissure encloses the cranial olfactory foramen.
The parietotectal cartilage is related to the fenestra narina and encapsulates the anterior chamber, on which it is dependent for its form. The paranasal cartilage encapsulates the olfactory chamber and gives rise to the lamina transversalis anterior, concha, planum antorbitale, and posterior maxillary process. The ectochoanal cartilage has become secondarily associated in lizards with the functioning of Jacobson's organ.
A Review of the Hydridae and Two New Species of Hydra from Natal
Authors: Ewer R.F. 
Published: August 2010

Summary.

Two new species of Hydra from Natal are described.
The classification of the Hydridae is discussed. It is concluded that Schulze's genus Pelmatohydra is no longer valid and the genus Hydra should be extended to include the forms previously classified as Pelmatohydra. It is considered desirable to defer consideration of subspecific classification until the descriptions of many of the species have been completed:
Summaries are given of the descriptions of the species known to date.
The Eyelids and Spectacle in Geckos
Authors: Bellairs A. D'A. 
Published: August 2010

Summary.

The eye‐coverings of three species of geckos belonging to the genera Coleonyx, Stenodactylus and Ptenopus have been studied by means of serial sections.
In Coleonyx true eyelids and probably a small nictitating membrane are present and there is no brille or spectacle. The relationships of these structures to the cornea, Harderian gland ductules and lachrymal canaliculi are essentially similar to those in Lacerta, and conform to the characteristic saurian pattern.
In Stenodactylus and Ptenopus a brille is present, and is surrounded by prominent extra‐brillar fringes. These structures are very extensive in Ptenopus and contain muscle fibres. The relationship of these fringes to the ductules of the Harderian gland and to the lachrymal canaliculi which open into the subbrillar space indicates, however, that the fringes cannot be regarded as homologous with the eyelids of other lizards.
By demonstrating that true eyelids and a brille are not found in association, these findings are regarded as evidence for the palpebral origin of the brille in geckos which is therefore homologous with that in snakes.
The Early Development of the Fore‐limbs in Xenopus laevis.
Authors: Newth D.R. 
Published: August 2010

Summary.

The early development of the fore‐limb and the origin of the brachial sac in Xanopuslaevis are described.
The brachial sac is shown to arise as a split in the limb rudiment, not in communication with either the opercular chamber or the exterior at the time of its formation. A derivation of the brachial sac in phylogeny is suggested.
The formation of the fore‐limb rudiment is shown to be unlike that known in any other tetrapod vertebrate.
Observations on littoral sponges, including the supposed swarming of larvae, movement and coalescence in mature individuals, longevity and death
Authors: Burton Maurice 
Published: August 2010

Summary.

The pattern in early growths of encrusting sponges suggests a grouping consistent with the swarming and simultaneous settlement of the larvae.
Post‐larval sponges tend to move about and, as they come into contact with each other, coalesce.
This movement, accompanied or not by coalescence, appears to be continued throughout the early part of life and may persist throughout.
In the later stages special growth forms include the production of blunt processes, slender branches or plasmodia, which may lead either to coalescence or to the formation of new individuals.
Several new individuals may be formed from a pre‐existing individual by disintegration due to desiccation, predators or wave action.
A new definition of the word “individual” is proposed, with special reference to sponges.
Notes are included on longevity, senescence and death.
Lipuria in Tigers
Authors: Hewer T.F. , Matthews L. Harrison , Malkin T. 
Published: August 2010

Summary.Examination of urine from the bladder of a tiger and a tigress at postmortem, and of urine collected from the cages of other tigers, showed that considerable lipuria is a constant physiological feature in these animals. The total fat excreted was about 20 grams a day and it contained 6‐5 per cent. of unsaponifiable matter, of which 60 per cent, was cholesterol and the remainder, apart from small quantities of ketosteroids, of undetermined nature.A histological examination of kidney tissue from the tiger and from two tigresses proved that the fat was derived from the epithelium of the proximal convoluted tubules and did not come from direct glomerular filtration.Sections from the kidney of a lion showed abundant fat in the epithelium of the proximal convoluted tubules, and less in the distal tubules, but as none was seen actually in the lumen, it was not possible to assert that fat was being excreted.Sections from the kidney of a cheetah, an ocelot and a blue whale gave no certain evidence of fat excretion, but the blood plasma in some of the vasa recta was sudanophil, and may have represented lipaemia.The significance of the fat excretion in tigers is briefly discussed.Our thanks are due to the Zoological Society of London for their kindness in sending us samples of tiger urine and tissue from the kidneys of a tigress, a lion, a cheetah and an ocelot, and to Dr. R.A.M. Case for tissue from a blue whale.We are indebted to Dr. C.J.O.R. Morris for his kindness in estimating the ketosteroids for us.
The pituitaries of Amia, Lepidosteus and Acipenser.
Authors: Kerr T. 
Published: August 2010

Summary.

An anatomical and histological description is given of the pituitaries of adult Amia, Lepidosteus and Acipenser.
In Acipenser a hypophysial cavity is present, in the others it has been suppressed during development; otherwise the structure of the pituitary in all three appears to represent a more primitive level of the same type of organization as found in the teleosts.
A hypothetical scheme is outlined of relationships between the pituitaries of teleosts and of higher types.
Notes on the nasal fossa of a young Chimpanzee.
Authors: CAVE A. J. E. 
Published: August 2010

Summary.The nasal fossa of a six‐year old female Chimpanzee is figured and described in detail. Anterior ethmoidal sinuses are absent bilaterally. Posterior ethmoidal sinuses of supreme meatal origin are present unilaterally. The maxillary sinus manifests an intra‐frontal extension: an accessory ostium maxillare is present unilaterally.
Notes on the treatment of fish infected with Argulus
Authors: HINDLE EDWARD 
Published: August 2010

Summary.Exposure to a 1: 10,000,000 concentration of the gamma isomer of hexachloro‐cyclo‐hexane (“Gammexane”) is recommended for the treatment of fish infected with Argulus, and has been used with success for the eradieation of this parasite from three large tanks in the Society's aquarium.
The development of the inner ear of Xenopus laevis.
Authors: PATERSON NELLIE F. 
Published: August 2010

Summary.

From a study of the progressive development of the membranous labyrinth through various larval stages of Xenopus laevis, it is noted that, in essentials, the parts resemble those of the Phaneroglossa.
The semicircular canals are separated after the constriction of the auditory vesicle into a pars superior and a pars inferior. The horizontal canal is formed before the anterior vertical, the posterior vertical being the last to appear. This sequence agrees with that of some of the Phaneroglossa (Herter, 1921). The pars inferior produces the sacculus, the pars neglecta, the lagena and the pars basilaris, there being no tegumentum vasculosum as in Rana (Gaupp, 1904).
Several membranous structures of somewhat doubtful physiological significance were observed to be associated with the foramen utriculo‐sacculare, the sacculo‐endolymphatic orifice and the aditus partis neglectae. Probably, like the utriculo‐saccular valve of fishes (Pearson, 1936) and the utriculoendolymphatic valve of mammals (Bast, 1928), they serve to maintain an approximately constant pressure of endolymph within the labyrinth.
The perilymphatic system appears to differ from the Phaneroglossan condition mainly in having no true ductus reuniens, as a consequence of which the foramen perilymphaticum superius is lacking, and the single perilymphatic foramen is comparable to the foramen perilymphaticum inferius of Rana. An additional tympanal area is to be observed between the anterior part of the pars basilaris and the spatium sacculare.
The sacci endolymphatici are paired throughout and are not connected by anterior ascending or ventral processes. Only two pairs of calcareous sacs were observed in the partes spinales. In post‐metamorphic specimens the endolymphatic system could only be traced as far as the region between the fourth and fifth intervertebral foramina. This reduction of the spinal portion of the endolymphatic system, in conjunction with the well‐defined auditory receptor areas in the labyrinth, is not suggestive of primitiveness. Xenopus possesses several structural features which may be regarded more fittingly as neotenic than as primitive. Others, again, may be purely adaptive, and while it is admitted that it may be fallacious to draw conclusions from a few isolated morphological facts, it could be surmised that, anatomically, the membranous labyrinth and its associated endolymphatic and perilymphatic systems indicate a possible reversion of this form from a semi‐terrestrial to an aquatic habitat. At the same time, the same features could equally well be interpreted as an attempt in a purely aquatic form to approach the condition found in semiterrestrial Anura.
On the Harvestman, Opilio saxatilis (C. L. Koch)
Authors: SANKEY J. H. P. 
Published: August 2010

Summary.A brief history of the systematic position of Opilio saxatilis (C. L. Koch) is given. The genitalia of O. saxatilis and O. parietinus are described, that of the males in more detail since this sex shows the greatest differences. The external characters of the two species are reviewed and compared. Records of O. saxatilis are given and its distribution is discussed, and the ecology of this species is contrasted with that of O. parietinus. It is claimed that sufficient evidence exists for regarding O. saxatilis as a distinct species.
The origin of the segmental musculature of the tail of the Axolotl (Ambystoma)
Authors: FORD PETER 
Published: August 2010

Summary.

By means of vital stains the rudiments of the tail structures present in the posterior one‐fifth of the medullary plate were delineated and the extent of the chordal and somitic mesoderm remapped.
The cells that will form the myotomes of the posterior part of the trunk and the whole of the tail are present in the posterior medullary plate at stage 15. By stage 16–17 the trunk material is invaginated. The tail mesoderm is enclosed by the closure of the neural folds.
The neural folds of the posterior two‐fifths of the medullary plate are responsible for the formation of the dorsal and ventral tail fin (see 11 below).
Perichordal and other mesenchyme of the tail has its origin in the posterior medullary plate.
The lateral lips of the blastopore take part in the formation of the proctodaeum which produces sprouts growing forwards to meet the descending pronephric ducts.
By operative techniques (transplants, deficiency experiments, etc.) the degree of organization and the inductive powers of the posterior medullary plate were determined.
At stage 15 the posterior fifth of the neural plate is fully determined to form segmental muscular tissue. The establishment of its antero‐posterior axis, however, depends on the presence below it of the axial structures, the neural tube and notochord.
Extirpation of the posterior medullary plate results in deficiencies in somitic mesoderm of the tail and hind end of the trunk. Mesenchyme is present and is, no doubt, the product of the neural crest.
Medullary plate, whether its prospective fate be neural or muscular, possesses the power to form a tubular structure without the assistance of the neural folds.
In transplants the segmental tissue formed by the posterior medullary plate closely resembles neural tube cytologically, relating tail muscle to its origin in the medullary plate.
The neural fold of one side of the medullary plate is capable of forming a bilaterally symmetrical fin.
The presumptive rudiments of the tail possess remarkable powers of stretching.
On the Homology of certain elements in the Skull of Bufo regularis Reuss (Salientia).
Authors: SEDRA SHOKRALLA N. 
Published: August 2010

Summary.

A centre of ossification is described for the first time in the auditory region of Bufo regularis Reuss. A similar one is present in Calyptocephalus gayi (Reinbach, 1939), where it was identified as “supratemporal”.
This centre has been homologized here with the postfrontal bone present in Apoda and in the Miobatrachidae.
Since the postfrontal of one side fuses with the corresponding squamosal towards the end of metamorphosis, the name “postfronto‐squamosal” is introduced.
The development of the so‐called fronto‐parietal is followed in three species of Salientia, which were not examined by Eaton. It is found that this bone develops from one centre of ossification in all cases.
After comparison with fossil forms it is concluded that it must be regarded as a frontal only.
Observations on the Grey Seal (Halichoerus grypus) at Ramsey Island, Pembrokeshire.
Authors: DAVIES J. L. 
Published: August 2010

Summary.A brdding colony of the grey seal was studied in the autumn of 1947 at Ramsey Island. The arrival of both sexes at the breeding grounds is discussed and also their behaviour prior to the birth of the calves. The history of the calf while on the beach is summarized, and calving rate, sex ratio and infant mortality are discussed. The movements of the immature and non‐breeding population are dealt with, and a description is given of the fur colour and age and sex distinctions. An attempt is made to elucidate population dynamics and the status of the species in South Wales. It is postulated that the Ramsey seals are traditionally cave‐breeders and that open beach breeding is a recent habit. Finally a comparison is made between the development and behaviour of Ramsey seals and those of Scottish colonies. It is shown that at Ramsey the adults are less dependent on land and the young are generally more precocious.