摘要:

In toad tadpoles the different stages of the development in the genital system (gonads and Bidder organs) are closely connected with the reaching of the different metamorphie stages; on the contrary they do not depend upon the time required by the single specimens to attain the metamorphosis.

ISSN:0373-4137    

DOI:10.1080/11250005809438281

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Genital blastemata of toad tadpoles are hardly sensitive to sperimental treatments with sexual hormones. Also progesterone (which is maseulinizing on the gonads of tadpoles ofRana) does not affects the development of gonads and Bidder organs in tadpoles ofBufo bufo.

ISSN:0373-4137    

DOI:10.1080/11250005809438282

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Homing pigeons alwais show, after an appropriate rotatory stimulation, a peculiar electric activity of cerebellar origin represented by prolonged rhytmic after discharges. In non orienting domestie races the after discharges are found in same individuals with frequencies that range from 10% in rock-pigeons of the squares to 40% in one peculiar italian race (Piacentini).

ISSN:0373-4137    

DOI:10.1080/11250005809438283

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The importauce of the problem of the sexual processes inColpodais pointed out. The first series of experiments made in order to induce conjugation inC. cucullusis described. The meaning of some stages of the life cycle 19 discussed, in relation to the possibility of the appearance of the mating reaction.

ISSN:0373-4137    

DOI:10.1080/11250005809438284

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

A research is made on the pulsation rate of the contractile vacuole in normal and treated clones ofColpoda cucullus. Both cultures treated that were put again back into the normal medium, one for twelve days, the other for thirteen days, show the same pulsation rate as the normal ones. The speed of the contractile vacuole formation seems to be related to the food vacuoles. Some of the results obtained in this research are compared with those which have been given from Friscii onParamecium.

ISSN:0373-4137    

DOI:10.1080/11250005809438285

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The values of resistance to the experimental environment (different concentrations of NaPAS in the medium) show high differences in different stages of the life cycle ofColpoda cucullus.The highest values have been seen in the animals near to the reproductive cyst, the lowest ones in the animals near to the resting cyst or just escaped from that. The value of the resistance seems in connection with the higher or lower food quantity of the organisms.

ISSN:0373-4137    

DOI:10.1080/11250005809438286

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

ISSN:0373-4137    

DOI:10.1080/11250005809438287

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The Author has studied the spermatogenic cycle inHydromantes italicusDunn. The preliminary results, based on observations carried on the animals captured and killed from November to May, are reported.

ISSN:0373-4137    

DOI:10.1080/11250005809438288

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

ISSN:0373-4137    

DOI:10.1080/11250005809438289

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The Author demonstrates the presence of the lamina cribrosa in the skin of soma Anuran Amphibians:Phryaobattracus uatalensis; Phrynobatracus perpal— natus; Hemisus marmorutum: Hyperolius marmoratus; Leptopelis bocagei; Kas— sina sp.. The nature and characters ot' such formation correspond to the descriptions abready known for other similar cases.

ISSN:0373-4137    

DOI:10.1080/11250005809438290

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor