10 F. J. F. Barrington, 



into this group and no explanation of the mucin in its cells could he 

 given. 



It is therefore evident, that in cats, during the first half of preg- 

 nancy, the epithelial cells of Bartholin's glands become rich in mucin : 

 this reaches a maximum early in the second half and then remains 

 stationary till a few days after parturition when it begins to decrease 

 fairly rapidly, first at the expense of the amount of mucin in each indi- 

 vidual cell, and later, by the cells containing mucin becoming fewer, 

 finally, in the late stages of lactation, all the cells are short or flattened 

 and hardly any contain mucin: this change in the appearance of the 

 cell is accompanied by a change in the secretion seen in the lumina, 

 from mucin to the homogeneous substance. Exceptionally oestrus may 

 occur during lactation, and then it is accompanied by the change in 

 the gland cells already described. These facts suggest that during 

 pregnancy the glands prepare themselves for some unusual secretory 

 effort, which begins at, or soon after, parturition and lasts approxima- 

 tely while the uterus is involuting, they then settle down into a resting 

 condition. If, as occurs in the mare, oestrus in the cat took place a few 

 days after pregnancy, the condition of the glands at parturition could 

 be easily explained. That it does not, at any rate when the kittens 

 are allowed to live, is shown by the fact that cats do not usually litter 

 at intervals of two and a half months. The change in Bartholin's glands 

 must therefore be a true phenomenon of pregnancy and not of oestrus 

 occurring shortly after parturition. Further, though the glands in both 

 instances are rich in mucin, there are slight histological differences: 

 the glands of late pregnancy never being quite as completely formed 

 of the tall columnar cells as are those of oestrus. In the four cases 

 mentioned where a large amount of mucin was present in the gland 

 although lactation was profuse, the period was only known in one, 

 in which it was between six and seven weeks after parturition. The very 

 marked mucinous type of gland was also found in one cat, about three 

 weeks after parturition, when the kittens had been taken away and 

 lactation had ceased. 



