ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00495.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

摘要:

Summary.An intersexual specimen of the wild brown ratR. norvegicusis described, in which the derivatives of the urogenital sinus have developed so that externally the animal is a female, whereas internally the gonads, ducts and accessory glands are male, though imperfect. The possibility of this condition being produced by the ante‐natal action of oestrogenic substances on a genetic male is discusse

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00496.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00497.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

摘要:

Summary.The following new forms are described either from caves or as epigaean species in the Himalayan area:Glenniea nova, Orthomorpha (Kalorthomorpha) almorensis. Chondromorpha kaimura, Sundanina septentrionalis, Glyphiulussp.,Siphonophora larwoodiandSaroxenus mirus.The cavernicolous genusGlennieaTurk is re‐studied and re‐described as well as its type speciesG. indicaTurk. The genusSaroxenusoften regarded as a doubtful one is re‐instated and its range extended to the continent of Asia by the discovery of the new species. Some faunistic notes on the collection are appended.All type specimens of the new species are, at present, in my colle

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00498.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

摘要:

The systematic position of the mongoose named by GrayHerpestes semitorquatus, and based on a specimen collected by Sir Hugh Low on the mainland of Borneo opposite Labuan Island,i. e.Brunei, has always been somewhat of a puzzle. Very few typical specimens are known and all of these come from the distributional area ofHerpestes brachyurus.The type skull in the British Museum which I have examined, shows no relevant differences from skulls ofH. brachyurusof comparable age. There is also no difference in proportions, the nakedness of the soles, nor in the hair structure between the two groups. The only difference that remains is that in colour.Herpestes‐brachyurusis a very dark animal with a lot of black, whereas inH. semitorquatusthe black pigment is greatly reduced, making the red ground colour predominant. The conclusion that I draw, is that the red and the blackish short‐tailed mongooses are colour mutants of the same species, the oldest name of which isH. brachyurusGray. This conclusion is emphasized by the fact that both the black and the red mutants vary geographically, and that the characters by which “Herpestes brachyurus sumatrius” Thomas from Sumatra differs from “H. b. rajah” Thomas from Borneo, are the same as those by which “Herpestes semitorquatus uniformis” Robinson and Kloss from Sumatra, differs fromH. s. semitorquatusGray from Borneo. In both cases the Sumatran animal is more uniform in colour, with a dark tail, whereas the Bornean animal is more finely speckled, and has a tail that is lighte

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00499.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

摘要:

Summary.1. The nature of the brille or tertiary spectacle in lizards and snakes is discussed.2. The morphology and relations of the orbital glands, conjunctival or subbrillar space and lachrymal duct system were investigated in ten different species of lizards, two of amphisbaenids, and fifteen of snakes.3. In all lizards, except one anguimorphine form,Pygopus, not examined by us, and inSphenodon, the Harderian gland discharges by separate ductules into the conjunctival or sub‐brillar space, on the deep surface of the nictitating membrane when this is present. The lachrymal duct always arises by two puncta and canaliculi from the conjunctival space on the deep aspect of the lower lid. This relationship is not influenced by the replacement of the lids by a brille, and it is suggested that this was the condition in the primitive ancestors of the Rynchocephalia and the Lacertilia.4. In the two amphisbaenids studied,Trogonophis weigmanniandAmphisbaena fuliginosa, a well developed sub‐brillar space is present. The lachrymal duct arises from this by a short wide communication, and the Harderian gland discharges both into the sub‐brillar space and into the lachrymal duct. With regard to the structures studied, these reptiles exhibit greater ophidian than lacertilian affinities.5. In snakes varying relationships are found between the Harderian ducts, the sub‐brillar space and the lachrymal canaliculus. In the more primitive types (e. g.Constrictor, Cylindrophis) the Harderian gland discharges directly into the sub‐brillar space as well as into the lachrymal duct. In “typical” snakes (e. g.colubrines and vipers), the Harderian gland discharges by a single duct into the upper end of the lachrymal duct only, and has no direct communcation with the sub‐brillar space. The lachrymal punctum is minute, and the lachrymal canaliculus enters the dilated lachrymal duct in a peculiar and characteristic manner.6. The lizard,Pygopus, not examined by us, shows conditions which may be regarded as representing a transitional stage between those in typical lizards and in snakes. Here the Harderian gland discharges into the lower of the two lachrymal canaliculi, and not into the sub‐brillar space.7. These findings are discussed in the light of current theories of ophidian phylogeny; the hypothesis of the origin of snakes from burrowing ancestors in particu

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00500.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00501.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

摘要:

Summary.Miss H. Frazer has given a brief general account of the mouth‐parts ofDysdercus intermedinsin her paper on the transmission of internal boll disease of cotton. In the present paper this description is amplified and augmented.The arrangement of the sclerites forming the head capsule ofD. intermediusis described. The maxillary plates have internal projections, the maxillary processes, which support the stylets in the anterior part of the head.The sucking pump, described as the pharynx by many authors, is an external chamber and not a true pharynx. It is formed by the flexible dorsal epipharynx, to which are attached the dilator muscles, and the rigid, ventral hypopharynx. The anterior end of the hypopharynx is drawn out into the pharyngeal duct which is inserted into the suction canal between the stylets.The two pairs of stylets are enclosed in a chamber, the stylet pouch, formed inside the head by the invagination of the outer wall of the head capsule and by the wing of the hypopharynx. The mandible is the outer of the two stylets. The protractor muscle of the mandible is attached to the mandibular lever and not directly to the stylet; the retractor muscle is directly attached to the base of the mandible. The maxillary stylet represents the lacinia of the maxilla of other insects, the rest of the appendage forms the maxillary plate. Both the pro‐ and retractor muscles of the maxilla are attached to the base of the stylet. There are no maxillo‐mandibular muscles.The saliva is forced down the salivary canal between the stylets by a highly developed salivary syringe. Two salivary ducts, their openings guarded by simple valves, open into the pump chamber. There is no valve at the exit of the common ejaculatory duct which runs through the body of the hypopharynx and opens into the salivary canal between the stylets.The epipharynx is pierced by two series of pores leading to sensory cells lying dorsal to the epipharynx. Prom their position these cells are supposed to be a gustatory organ.Dysdercus intermediushas paired maxillary glands lying inside the maxillary plates and opening by numerous small pores on their anterior faces. It is suggested that the secretion from these glands may be to lubricate the stylets or to help to bind the stylet bundle together and so strengthen it.The salivary glands are of the four‐lobed type with duct‐like accesso

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00502.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

摘要:

Summary.1. The growth and the spawning and feeding habits of nine species of British freshwater fish are described. These species are:—Rutilus rutilus, Scardinius erythrophthalmus, Leuciscus leuciscus, Abramis brama, Blicca bjoerkna, Gobio gobio, Perca fluviatilis, Acerina cernuaandEsox Lucius.2. Growth has been studied by the use of scale‐reading. Individual growth‐rates vary greatly, the range in size of any age group nearly always exceeding the differences in average length between that age group and the next junior and senior age groups.3. In the cyprinids, male and female fish are at first equal in numbers, but the males die off more swiftly than the females and are in the minority in the senior age groups.4. Freshwater fish show a wide range of choice of foods; such species asRutilus rutilusandScardinius erythrophthalmusmay be herbivores or carnivores as opportunity offers.5. Two instances have been found of closely related species sharing an ecological niche. These species are:—Abramis bramawithBlicca bjoerkna, andPerca fluviatiliswithAcerina

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00503.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY

摘要:

Summary.1. Buds ofHydra vulgarisimmediately after separation from the parent migrate upwards towards the water surface. This reaction is a negative geotaxis, and not a response to a gradient in oxygen concentration; it takes place in water of any oxygen concéntration.2.Hydrais known to be photopositive. The gravity reaction of buds is much more strongly affected by light coming from below than by light coming from the side. Animals which have been grown for two generations in bottom light behave in the same manner as normal animals from stock cultures. This effect of bottom light is discussed in terms of the known mechanism of the animal's light reaction, and it is concluded that no new complexity in type of response or in neuromuscular organization need be postulated to account for it.3. An increase in carbon dioxide content of the water could not be shown to have any significant effect on the strength of the gravity reaction of buds, but evokes negative geotaxis in adultHydra.Neither an equal lowering of pH by hydrochloric acid nor a reduction in the oxygen concentration has any affect.4. The gravity response of buds lasts for at least three days after separation from the parent.5. If a freshly separated bud is given food it ceases its upward migration.6. Walking of buds is fastest at about 22°C. Abnormalities in locomotion begin to appear at slightly higher temperatures, and at 26°C. walking stops.7. In upward migration the orientation to gravity is direct, without trial movements.8. The gravity reactions described are of biological significance. That of buds acts as a method of distribution and prevents local overcrowding. The response evoked in adults by carbon dioxide serves to bring them up to the surface when there is likely to be a shortage of oxygen lower do

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1947.tb00504.x

出版商:Blackwell Publishing Ltd    

年代:1947

数据来源: WILEY