GONADS AND THE PITUITARY BODY 



in many of which a free communication between the peri- 

 toneal cavities was estabhshed usually by the method of 

 Sauerbruch and Heyde. However, there is evidence that the 

 effects discussed here largely depend upon the transfer of 

 blood from one animal to the other rather than upon a trans- 

 fer of the fluid of the peritoneal cavity. Hill (1932) has par- 

 ticularly studied this aspect of the problem; he preferred not 

 to join the peritoneal cavities. 



The principal experiments can be summarized as follows t^*^ 



1. cf'd^. This type of parabiosis is accompanied by no 

 change in either rat (5). 



2. 9 9 . The oestrous cycles of the two animals occur in- 

 dependently and are unaffected or only slightly affected (4, 



5, 9)- 



3. cf 9 . No changes occur in the testis and prostate (2) or 

 degenerative changes are later observed (i, 5). 



Various opinions on the changes in the female genital tract 

 have been expressed (i, 4, 9, 15). The oestrous cycles may 

 recur normally for a long period or may be succeeded, a few 

 days after parabiotic union, by a prolonged dioestrous stage. 

 Cystic follicles may be found in the ovaries or the early ovari- 

 an changes may be described as a combination of luteiniza- 

 tion and follicle growth. 



4. cTsT- The genital organs of the normal male are in- 

 creased in size. The castration changes in the secondary sex- 

 ual organs of the castrated male are not affected (i, 5, 10). 



5. cf 9 . Hypertrophy of the male genitalia may follow 

 (5). Yatsu (2), however, could find no change in the testes or 

 prostate. 



6. 99. The changes usually occur only in the normal fe- 

 male (occasionally oestrus may appear in the spayed rat). 



*» The experiments here summarized were nearly all performed in rats after 

 puberty, cf and 9 refer to normal male and female rats; (sT refers to a castrated 

 rat, ?, to a spayed rat. cf 9 refers to parabiosis between a normal male and a 

 normal female rat; d^ ? refers to parabiosis between a normal male and a spayed 

 female, and so on. 



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