86 THE SHEPHERD'S MAKUAL. 



and sometimes will extend beyond his own immediate progeny, 

 and modify that of future sires upon the same dams. While this 

 influence of the first male is not so general as to afford a basis for 

 a rule, yet observation has shown it to be of sufficient force to 

 entitle it to the consideration of careful breeders. The influence 

 of the ram upon the sex of the progeny, is something equally 

 worth considering, although it is as yet somewhat undetermined. 

 In theory it is supposed to be exerted through a natural provision 

 by which the fecundity of a race increases along with the better 

 opportunities it enjoys for its subsistence. Thus it is reasoned, 

 when animals are well fed and cared for, and are not allowed to 

 breed early, their produce will be in greater part females, permit- 

 ting a more rapid increase, in consistence with their more favor- 

 able opportunities for development. On the contrary, when ani- 

 mals are sparely fed or exhaustively used, and allowed to breed 

 early, the tendency of nature is to restrict the production by the 

 birth chiefly of males. This theory receives confirmation through 

 the tendency of the early breeding and exhaustively producing 

 Jersey cow to have male calves, and through some observed facts 

 in sheep breeding. 



One of the facts directly pertinent to this matter is recorded in 

 the Annales de V Agriculture Franpaise, as follows. It was proposed 

 at a meeting of the Agricultural Society of Severac, to divide a 

 flock of ewes into two parts, that an experiment might be made to 

 test the question of breeding for sex. One flock of ewes was put 

 into an abundant pasture, and was served by very young rams. 

 The other flock was put into a poorer pasture, and was served by 

 rams not less than four years old. The result is given in the tables 

 which follow ; the flock from which the excess of female lambs 

 was expected, being served by rams 15 months to 18 months old, 

 produced three twin births, and the flock expected to yield the 

 most male lambs, and which was served by rams over 4 years old, 

 produced not one double birth. 



Flock for female lambs served by rams under 18 months old . 



Sex of the Lambs. 



Age of Ewes. Males. Females. 



Twoyearsold 14 26 



Three years old 10 29 



Four years old 5 21 



Total &5 76 



The excess of female lambs in this flock is very remarkable, ag 

 is also the excess of male lambs shown in the next table. 



