THE PITUITARY BODY 



in their relative gonadotropic potency in rabbits and rats. 

 These observations are not new but are here more accurately 

 confirmed. It is not possible exactly to state how difFerences 

 are related to the distribution of various pituitary gonado- 

 tropic hormones in the extracts. Ox pituitary extract is prob- 

 ably much less potent in follicle-stimulating hormone and 

 richer in luteinizing hormone; perhaps it contains more 

 gonadotropic hormone "antagonist," the effects of which 

 would be more marked in the rat (repeated subcutaneous in- 

 jections) than in the rabbit (single intravenous injection). 

 The reader is also referred to later discussion (pp. 1 15-17). 



TABLE 1 



One other report, unrelated however to pregnancy, may be 

 mentioned here. Bachman (1936) observed that in very 

 young or juvenile rabbits (15-90 days old) the outstanding 

 ovarian change in response to sheep pituitary extract or 

 prolan might be Hmited to the interstitial stroma in which 

 there appeared large polyhedral cells taking lipoid stains. If, 

 on the other hand, prompt and extensive luteinization of the 

 membrana granulosa occurred, there might be no change in 

 the interstitial tissue. Also, in very young rabbits gonado- 

 tropic hormone could cause the formation of corpora lutea 

 without associated progestational changes in the uterus. 



According to Morgan (1935), extract of beef anterior lobe 

 or prolan alters the motility of the uterus of the nonanesthe- 



[70] 



