16 P. J. F. Barrington, 



mais as the guinea-pig where the muscular capsule is not very thick, as in 

 the cat, nor the gland complicated by a large dilated duct as in the rat. 

 It was found that the glands of five guinea-pigs, varying from 550 grams 

 to 810 grams, and castrated in adult life 5^2, 6, 6, 7, and 10 months 

 previously, weighed respectively .054, 075, .121, .075 and .095 grams: 

 while twenty-five normal guinea-pigs varying from 400 to 765 and 

 averaging 517 grams had Cowper's glands weighing from .102 to .255 

 grams and averaging .161. The effect of castration on the mucin 

 was found to vary in different animals. In the guinea-pig there was 

 hardly any effect at all when the adult was castrated, the mucin 

 reaction both of the cells themselves and of the secretion in the lumina 

 of the ducts and acini was quite as marked as in the intact animal: 

 the only obvious histological difference was that the lobes of the glands 

 were separated from each other by a greater thickness of interstitial 

 tissue and muscle, the individual gland cells were rather smaller and 

 the nuclei on the whole not so compressed or deeply staining: the two 

 last differences were very slight. If the animal was castrated when 

 young e. g. five weeks old, the same differences occurred but were 

 much more marked, the gland resembling that of an animal of the age 

 at which it was castrated, and like the latter showing a well marked 

 mucin reaction in each individual cell. 



In the rat castration in the adult produced a more marked effect 

 on the Cowper's glands than in the guinea-pig in three to four months 

 the acini became much fewer and the cells much smaller but both they 

 and the secretion in the duct still gave a mucin reaction. The glands 

 of the water vole (Arvicola amphibius) in autumn were found to nor- 

 mally have taken on an appearance very like those of the rat some 

 months after castration. 



In the cat no animal was castrated for the purpose of seeing the 

 effect on Cowper's glands but the glands of a considerable number 

 which had been castrated at an unknown date were examined. The 

 glands were all small. The pad of fat that normally exists between 

 the capsule and the gland was usually increased at the expense of the 

 glandular tissue. Some glands gave no mucin reaction in their cells 

 at all, most gave it slightly and a very few moderately, none at all 



