THE PTTUITARY BODY 



only a slight and transient secretion of milk was observed 

 after parturition. As in the hypophysectomized mouse (but 

 not the rat), the corpora lutea of the hypophysectomized 

 guinea pig rapidly regressed. 



Successful hypophysectomy in the rabbit is best performed 

 by employing an orbital (Firor), parapharyngeal (Smith and 

 White), or a buccal approach (White); other methods, such 

 as by the use of a nasal trocar (Kosakae, 1930), of hot wax to 

 cause a necrosis (Krieser and Partos, 1935), or of radon 

 (Lacassague and Nyka, 1934) or X-rays (Mogilnitzky and 

 Podljaschuk, 1928) not only are more likely to damage ad- 

 jacent structures but also are less likely to effect the com- 

 plete removal or destruction of the gland. All the effects of 

 hypophysectomy in the rabbit appear to be due to the re- 

 moval of the pars glandularis. 



By means of acute experiments in rabbits from which the 

 pituitary was removed. Fee and Parkes (1929) showed that 

 ovulation, which normally takes place about 10 hours after 

 coitus, could be prevented provided that hypophysectomy 

 was done within less than i hour post coitum. If the operation 

 was performed later than i hour after copulation, ovula- 

 tion occurred and the corpora lutea underwent normal but 

 perhaps slower development than in control rabbits (Deanes- 

 ly. Fee, and Parkes, 1930), These observations were con- 

 firmed and extended by Smith and White (1931) who found 

 that the corpora lutea continued to grow only for about 1 

 days; after 8 days they had definitely begun to regress. The 

 early development of the corpus luteum in the rabbit may 

 therefore take place in the absence of the pituitary (but not 

 necessarily in the absence of pituitary secretion). 



The other effects of hypophysectomy in immature or adult 

 rabbits resemble those in other mammals (White, 1933; 

 Saito, 1934). White also found a considerable atrophy of the 

 liver and spleen in hypophysectomized adult rabbits. Ac- 

 cording to Firor and Reynolds (1933), spontaneous contrac- 



[68] 



