摘要:

The aquatic habit of members of the Pipidae seems to have resulted in the retention of a number of neotenic features, and these are evident in the inner ear as well as in other systems of organs.From a comparative study of the morphological details of the inner ear of adults ofHemipipa carvalhoi, Hymenochirus curtipesandXenopus laevis, juvenilePipa pipaand larval stages ofHemipipa, XenopusandRana fuscigula, it appears that the arrangement inHemipipais the least specialized, while the inner ear ofXenopusclosely resembles that of amphibious Anura.Attention is drawn to Witschi's conclusions (1947–1956) that in larval forms ofRanaandXenopusthe lungs act as sound receptors, associated with which is the temporary development of certain auxiliary bronchial structures. In the present observations these structures are interpreted otherwise, and no definite conclusions are reached as to their participation in the auditory mechanism.Variations in the inner ear of the four species of Pipidae studied appear to strengthen opinions regarding the somewhat unsatisfactory classification of the family.HemipipaandPipafall naturally into the subfamily Pipinae, but the marked differences betweenHymenochirusandXenopus, not only in regard to the inner ear, but also in other anatomical features, suggest that these two genera should be relegated to separate subfamilie

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05598.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

In adult wild mallards the penis weighs about 0·6 gms (0·05 per cent of body weight) for most of the year but increases to a weight of almost 3 gms. (0·3 per cent of body weight) at the height of the breeding season. In immature birds which had reached adult body weight the average penis weight was only 0·03 gms. (0·0026 per cent of body weight). The breeding season penile enlargement could be prevented by castration early in the spring. Evidence that Testosterone administration can cause enlargement of the penis in adult mallards was also obtained. Unilateral adrenalectomy did not effect penile or testicular we

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05599.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

Twenty species of Symphypleona are recorded from the Gambia of which twelve are new to science and are described. A brief survey is given of the chief vegetation and soil types to assist in classifying the habitat references in the text.Sminthurinus stenognathusBörner andBourletiella spathaceaBörner are noted as probably extending throughout the northern savanna belt of the Ethiopean region, having been recorded from both ends of this vegetation zone.Sminthurides cf. ramosusandSminthurus macrocerosDenis are recorded as occurring on both sides of the Atlantic and it is suggested that resistant stages which allow them to live under savanna conditions also fit them for long distance wind dispersal. In an appendix (vide infra) some information is given on some species ofSminthuridesfor comparison with species newly described here, and lectotypes are established forS. melanotusandS. spegazziniifrom material in the British Museum collectio

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05600.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

The gestation period has been estimated in 34 pregnancies which have occurred in the Birmingham colony of rhesus monkeys. The placental sign could be identified in 16 of them and the gestation periods in this group varied between the limits of 158 and 173 days. No placental sign could be recognized in the other 18 pregnancies and the records of menstrual bleeding could not be interpreted to give reasonably consistent estimates of the duration of pregnancy.One prolonged labour is described in detail and the exceptionally heavy baby, weighing 840 g, was finally born after a normal gestation period of 165 days.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05601.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

The evolution of the pulmonate genital system is traced from a prototype exemplified by the tectibranchActeon. Many features remain almost unchanged in the genera studied, but there is a progressive degree of separation and specialization of the male and female ducts. Some genera of the Ellobiidae, such asPythia, are undoubtedly primitive. However, it is suggested, following an investigation of the reproductive system ofChilina robustior, that the Chilinidae may stand closest to the ancestors of the Stylommatophora and the Hygrophila.The sexual cycle inPhysais compared with the protandric sequence found in the primitive Ellobiidae. Similarly, the course of the vas deferens through the mantle wall and the development of the penis from a separate anlagen are also thought to be relies of the ancestral condition.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05602.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

Social behaviour of wild‐white hybrids and of tame albino rats in experimental colonies is compared, with special reference to the intensity of ‘social stress’, and contrasted with that of wild rats (described in a previous communica

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05603.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

Brumptia bicaudatais redescribed and redefined, with particular reference to the genital organs, hermaphroditic pouch and genital papilla. A ciliated valve which separates the vesicula seminalis and ejaculatory duct is described; the ejaculatory duct is lined with ciliated epithelium. The subfamily Brumptinae is redefined.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05604.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

A comparative study of topotypes ofSaccoglossus ruber(Tattersall)S. serpentinus(Assheton) andS. cambrensisBrambell&Cole shows that they are conspecific, and ought henceforth all to be designatedS. ruber(Tattersall).The following characteristics distinguishS. ruberfrom all other species of the genus:— 4 to 6 concentric rings of longitudinal fibres in the proboscis, one proboscis pore on left of stalk, proboscis 3 to 7 times the length of the collar, 45 to 95 pairs of branchial pores, 6 to 12 oesophageal pores—2 to 5 rudimentary, 5 histologically distinct regions in the collar and 3 in the oesophagus.Munsell, Ridgway and I.S.C.C.—N.S.B. colour designations for the various regions of the body have been tabu

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05605.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

A study of passive movements and an analysis of the prehensile patterns of movement of the anthropoid ape hand was carried out in two young chimpanzees and one young orangutan, all approximately two years old at the time of study. The passive movements compare closely with those of a human child except in respect of the wrist and metacarpophalangeal joints of the fingers; in the case of the former joint, while flexion was very full, extension was limited. Passive movement of the metacarpo‐phalangeal joints was also very full, movement being limited only by contact of the fingers with the palm. A “double‐locking” mechanism of the 2–5th digits taking place at the metacarpo‐phalangeal joints is described. The anatomical basis of these movements and the “double‐locking” mechanism is discussed. Active movements were studied in terms of the prehensile patterns of the human hand (Napier, 1956) and it is shown that, while there is evidence of a functional duality of prehension in the hands of young anthropoid apes, the execution of the two grips differs profoundly from that of Man; the difference is discussed in terms of the disproportion in the length of the thumb and fingers in apes. It is suggested that the “double‐locking” mechanism of the fingers compensates in some measure for the ineffectiveness of

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05606.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

The pronephric systems of eightNeoceratoduslarvae ranging from 11·5 to 16 mm. total length were analysed quantitatively and the measurements were treated statistically for two groups of mean total length 11·5 mm. and 15·3 mm. In the 15·3 mm. group the means of the measurements of the nuclear population, total volume of cells, overall pronephros volume and the internal surface area of the tubules show a significant superiority over the means of those in the 11·5 mm. group, but the mean of the glomus length is significantly lower. The individual cell volume which does not change significantly had a maximum range of 6500–6800 μ3. Quantitatively in terms of cell volume and qualitatively the pronephric systems of larvae ofNeoceratodus, Anura and urodeles are similar, and have evolved in a parallel manner during ph

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1960.tb05607.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY