The Action of Animal Extracts on Milk Secretion. 



experiments, determining the amount of milk which could be drawn from the 

 udder by an aspirator before and after the injection of various extracts into 

 a vein of the ear. They record a very striking action of infundibulin, the 

 amount of secretion being increased in one experiment as the result of a 

 single injection from 5 drops to 400 drops of milk in periods of five minutes ; 

 they have also obtained a galactagogue action from extracts of corpus luteum, 

 thymus and pineal gland. Although we have not been able to determine 

 this action in the case of tbe two last mentioned glands, our experiments 

 upon the pituitary and corpus luteum have yielded results, in the cat and 

 dog, similar to those obtained by Drs. Ott and Scott in the goat, and We shall 

 await with interest the publication of the details of their experiments. In 

 any case the credit of the discovery of hormones which influence milk 

 secretion belongs to them, and our results, although arrived at on other 

 .vnimals and by a somewhat different method, are in the main confirmatory of 

 those which the American authors have established, at least for the early 

 period of lactation. 



[Note added March 31, 1911. — Since this paper was read, Dr. Mackenzie 

 has found that extracts both of involuting uterine mucous membrane and of 

 mammary gland itself are markedly galactagogue, and that with regard to the 

 action of pituitary extract, the source of this extract appears to make no 

 difference to its activity; the extract of the bird's pituitary being quite 

 as active in promoting the mammary secretion as that of the mammalian 

 pituitary itself. He has also determined that atropine does not interfere with 

 the action of any of these galactagogues.] 



