SEX. 299 



on this theory, the observed results of ordinary farm- 

 practice are sufficient to disprove it. 



On the Michigan Agricultural College farm, when 

 under my direction, the births for ten years were as 

 follows: Sheep, 102.5 males to 100 females; cattle, 

 118.4 males to 100 females. 



The system pursued for the entire time was the 

 same. The rams were turned with the ewes every 

 forenoon during the breeding-season ; and the cows, 

 as a rule, were served as soon as they were discovered 

 to be in heat, the herd being frequently visited during 

 the day, and driven to the barn every night and morn- 

 ing. With very few exceptions, the females were 

 served during the first half of the period of heat, 

 which, according to the theory of M. Thury, should 

 have given a very large proportion of females. 



The records show some remarkable facts that will 

 be recognized by breeders as fairly representing the 

 general experience of farmers. In 1864 and 1865 the 

 bull-calves were 2.5 to 1 heifer ; in 1866 and 186T the 

 heifers were considerably in excess ; in 1868 and 1869 

 the heifers were nearly 2 to 1 bull ; in 1870 the bulls 

 were decidedly more numerous ; and in 1871 and 1872 

 there were more than 2 bulls to 1 heifer. In 1872 

 there were 2 rams to 1 ewe, and the bulls were nearly 

 in the same proportion to the heifers, which would 

 seem to indicate some peculiar influence of the season 

 in favor of the males. In 1871, however, the bulls 

 were largely in excess of the cow-calves, and there 

 was quite as decided a preponderance of females among 

 the sheep. 



On "Waushakum farm, according to Dr. Sturte- 



