摘要:

Previous researches have shown that in flies the landing reaction threshold is lower at lower light intensities. Since it is commonly observed that flies do not fly in darkness it has been hypothesized that the lowering of the landing reaction threshold may be due at least partly to a decrease in general activity mediated by the cervical ocelli (which are known to have a dynamogenic effect on other kinds of behaviour.

ISSN:0373-4137    

DOI:10.1080/11250008009440325

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Architectural pattern of the telencephalon, diecenphalon and mesencephalon of Polypterine fishes (Osteichthyes, Brachiopterygii).

ISSN:0373-4137    

DOI:10.1080/11250008009440326

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Preliminary results on the effects of testosterone and cyproterone acetate (CPA) on the crested newt's sexual behaviour are reported. The intraperitoneal administration of testosterone to the castrated male did not reactivate sexual behaviour. Similarly the anti-androgen CPA did not affect courtship behaviour in short-term and long-term treated animals. Probably the mode of administration may influence the effect. Spermatophore deposition was impaired in the long-term treated males. Sexual behaviour of this amphibian does not appear to be exclusively androgen-dependent. However, further research is necessary to understand how androgens and pituitary hormones control the newt's sexual behaviour.

ISSN:0373-4137    

DOI:10.1080/11250008009440327

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Measurements of skull and horns in six subspecies ofRupicapra rupicapraL. (pyrenaica, ornata, cartusiana, balcanica, carpatica, caucasica) have been evaluated statistically.R. r. pyrenaicaandornatahave the smallest skulls, the closest horn bases, and obliterated frontomaxillary fontanelles. They have also similarly patterned winter coats. On the basis of such featurespyrenaicaandornataare separate from the other subspecies which do not seem to differentiate much from each other. On the other hand,pyrenaicahas a much smaller body size thanornataas well as the shortest and thinnest horns, whereasornatahas the longest and stoutest horns of all the subspecies examined. Furthermore, theornate'sfrontomaxillary fontanelle is much longer thanpyrenaica's.

ISSN:0373-4137    

DOI:10.1080/11250008009440328

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Adult mice when spatially separated from the opposite sex emit bird-like calls. These sound emissions have been recorded and analysed with a sound spectrograph. Calls consist of one or more groups of clear notes in rapid succession. Each individual note of 20–30 msec ranges from about 3 to 6 kHz with an interval of 100 msec between notes.

ISSN:0373-4137    

DOI:10.1080/11250008009440329

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The nuclear DNA content of 23 chondrichthyan species (9 Squalomorphii, 11 Batoidea and 3 Galeomorphii) has been studied. Their genome size ranged from 5.4 pg/N inRaja clavata(Batoidea) to 32.3 pg inEtmopterus spinax(Squalomorphii).

ISSN:0373-4137    

DOI:10.1080/11250008009440330

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Four days old mice raised by both parents are less active than contemporaries raised by the mother alone or by the mother and one strange adult female. This result leads to hypothesize a) the existence of a paternal influence which inhibits pup locomotor activity; b) that pup mouse activity is connected with environmental factors apart from the genetic component.

ISSN:0373-4137    

DOI:10.1080/11250008009440331

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

We report the results of a preliminary study on the biology ofTriturus alpestris apuanus(Bonaparte) andTriturus cristatus carnifex(Laurenti). The sample zone chosen was the Garfagnana. The water analysis of 14 stations, of three unoccupied ponds and of the “Troscia” pond, reveal that these Salamanders behave as “eury” species to the physico-chemical parameters of their environments. It is suggested that they belong to “biological accomodated” communities. Furthermore, three stations are considered with some detail which show particular characteristics, e.g. i) coexistence of newts and fishes; ii) very high salinity values; iii) coexistence ofT. a. apuanus, T. c. carnifexandT. a. apuanusneotenic stage; iv) high degree of morphological polymorphism.

ISSN:0373-4137    

DOI:10.1080/11250008009440332

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A probabilistic method, based on a Bayesian approach, is proposed for the evaluation of results obtained in experimental infections induced by microscopic eggs (or larvae) whose exact number is not directly known.

ISSN:0373-4137    

DOI:10.1080/11250008009440333

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A “natural” infection technique based on the uptake of eggs with feed is described. The ratio of the number of parasites recovered 14 days post infection to the number of eggs given (qratio) is close to 1 if few eggs are given (⋍ 5 per mouse). In the same conditions,qis less in mice infected with ⋍ 50 or ⋍ 500 eggs. The larger the number of parasites, the faster their spontaneous elimination. Total elimination or “self-cure” may be attained even in the case of large numbers. In mice infected with many eggs, following treatment with ionizing radiations,qis greater than in the controls.

ISSN:0373-4137    

DOI:10.1080/11250008009440334

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor