GONADS AND THE PITUITARY BODY 



of progesterone, but not by the injection of such a dose of 

 oestrin alone. Clauberg and Breipohl (1935) were able to pre- 

 vent the castration changes in the anterior lobe, also in adult 

 spayed female rats, by administering progesterone alone (7,5 

 rabbit-units in a period of 35 days). 



In so far as oestrus can be prevented or altered by the in- 

 jection of corpus luteum hormone, this effect may at least 

 partly depend upon an alteration in the pars glandularis. 

 According to Mahnert (1930), copulation is not followed by 

 ovulation in the rabbit if corpus luteum extract has been ad- 

 ministered previously. 



Wolfe (p. 130) concluded that the pars glandularis of the 

 sexually mature pig contained the least amount of the hor- 

 mone causing ovulation in the rabbit, if the pituitary was re- 

 moved from pigs, the ovaries of which contained actively 

 secreting corpora lutea. 



The internal secretion of the testis'-^ in relation to the secretion 

 of gonadotropic hormone{s) by the anterior pituitary. — There is 

 some direct as well as considerable indirect evidence indicat- 

 ing that the internal secretion of the testis lessens the secre- 

 tion (and storage) of gonadotropic hormone by the anterior 

 pituitary. For example, the administration of testicular tis- 

 sue or hormone may prevent or "cure" castration changes in 

 the pituitary of immature or adult castrated rats (Martins 

 and Rocha, 1931; Migliavacca, 1935). Some of the indirect 

 evidence has already been considered. The sexual difference 

 in the gonadotropic potency of the pituitary of very young 

 rats (the female pituitary is the more potent) appears to de- 

 pend upon the fact that the internal secretion of the testis is 

 liberated at an earlier age than is that of the ovary. In para- 

 biosis experiments the genital organs of the female of the ex- 

 periment 9 ^ are strikingly affected, whereas those of the 

 female of the experiment 9 c?" are not. Apparently the re- 

 moval of the testis also removes an organ inhibiting the lib- 



■"s No distinction between extracts of urine and extracts of testis is made here. 

 [155] 



