Pituitary Extract and Secretion of Milk. 83 



found that there was no change either in the amount or in the 

 composition of the milk for the twenty-four-hour period. 



We 1 have found that in the goat, within fifteen minutes after 

 the injection, there is invariably an increase in the quantity of 

 milk obtained and likewise in the percentage of fat. This has also 

 been observed by Hammond. In one of our experiments the fat 

 reached the high figure of 18 per cent, in the milk yielded after 

 injection, while the normal for this animal was about 5 per cent. 

 There is, however, a diminution in the quantity of milk obtained 

 at the next milking period but the fat content remains above the 

 normal for a day or two. The solids-not-fat of the milk do not 

 appear to be affected. 



The experiments which we desire to report on this occasion 

 were made on the cow. Two animals at different periods of 

 lactation were used. They were milked by hand, twice a day, 

 at 6 a.m. and 5 p.m., and records were kept of the amount yielded 

 and the percentage of fat for some days before and after the injec- 

 tion, as shown in the following tables: 



table I. 



Guernsey Cow; Age 12 Years; Weight 930 Lbs.; Last Calf Born More 

 Than One Year Ago. 





Weight of Milk in Pounds. 



Percentage of Fat. 



Morning. 



Evening. 



Morning. 



Evening. 



January 28 



5-9 



4-5 



4.8 



5-2 



29 



6.2 



4.8 



4.8 



5-2 



30 



5-4 



S-4 



4.6 



S-i 



31 



5-6 



5-0 



4.6 



5-3 



February 1 



5-8 



5-0 



4.0 



S-3 





S-9 



5-4 



4-3 



5-2 



3 



5-8 





S-i 





4 



3-3 

 S-9 



S-4 

 5-4 



4-8 

 4-9 





s 



5-0 



On February 3, at 4.30 p.m., this cow was milked dry; 4.7 

 lbs. of milk was obtained which contained 4.9 per cent, of fat. 

 She was in heat and was being examined by a veterinary surgeon 

 which caused some delay. At 5.15 p.m. a Ringer's solution extract 

 of eight whole ox pituitary glands (anterior and posterior lobes) 

 was injected into the external jugular vein, and at 5.30 the milk 



1 Our paper is in the press and will appear in the first number of the Quarterly 

 Journal of Experimental Physiology for the current year. 



