Studies in Milk Secretion. 541 



during the first weeks of a milking period than at any subsequent 

 time during the same lactation. 



The record given of Dora (II), August, 1893 to July, 1894, is 

 of her production as a two-year old. During this year she dis- 

 played a remarkable "holding out" power. In the second 

 month she fell off in the daily average nine per cent, but for the 

 next ten months she fell below her first average only twice and 

 then no more than three per cent. At the end of the tenth 

 period she declined so rapidly in milk that she was completely 

 dry before the close of the eleventh. In per cent of fat she 

 showed a variation which is found by these studies to be quite 

 common, namely, a decrease for the second or third four weeks, 

 and then a gradual rise to the close of the milking period. She 

 dropped her second calf August 30, 1894, three days more than 

 a year from her first calving. She " held out " in milk as a two- 

 year old better than during any succeeding year. 



Mollie (III) September, 1895 to September, 1896, displayed 

 almost as continuous a milk flow as Dora in 1893-94. Begin- 

 ning the first four weeks with a daih^ average of 35.25 pounds, she 

 did not decrease more than three per cent until the tenth period, 

 when she fell off 16 per cent and then declined rapidly until dry 

 in the thirteenth period. In per cent of fat she was higher 

 during the first month than at any other period except at the 

 last end of lactation. This was her fifth lactation and her sixth 

 calf was dropped 13)^ months after the fifth. 



Belva 2nd (IV.) September 1896 to Jul}^ 1897, likewise showed 

 much power in "holding out " in her milk flow. At the end of 

 the eighth four weeks, her daily average had not fallen below 

 that of the first period, but then she declined rapidly and went 

 dry at the end of the tenth four weeks. In per cent of fat she 

 shows much the same characteristics as were noted in Dora (II). 

 This was her record as a three-year-old and her third calf was 

 born a little less than a year after the second. 



Dais3^ (V.) September 1892 to July 1893, showed a decrease in 

 milk flow which is rather more than the average and at the same 

 time an increase in per cent of fat which is much greater than 

 the average. During the seventh month the per cent of fat rose 

 25 per cent above the average for the first four weeks and this 



/ 



