Autumn Management of the Flock 171 



should fail to be fertilized for lack of a second active 

 spermatozoon among the thousands produced. 



Ova produced by ewes. — In an investigation 

 made by Dr. F. H. A. Marshall of Cambridge 

 University, England, 55 ewes were slaughtered and 

 their ovaries examined during the mating season. 

 Of this number, 42 had discharged one ovum only ; 

 7 had discharged one ovum from each ovary; in 

 5 cases, two ova were discharged from one ovary ; and 

 there was 1 case in which two were discharged from 

 one ovary and one from the other. This number of 

 ova corresponded to the proportions of twins and 

 triplets common in the breed to which the ewes 

 belonged. Ewes that are in good condition may be 

 expected to produce two ova more frequently than 

 they would if in a low condition. 



The fact that the ewes that lamb earliest produce 

 more twins than the late lambing ewes is sometimes 

 held to show that the ram is most prolific early in 

 the breeding season. The more reasonable explana- 

 tion is that some ewes are sexually more active than 

 others and for the same reason come in season and 

 get in lamb first. Taking the ground that the ram 

 does not govern the number of lambs so long as he 

 is in reasonable condition, does not oppose the idea 

 that a male may transmit the fecundity of his dam to 

 his daughters, which would enable him to infiuence 

 in some degree the number of his descendants in 

 the second generation, but not in the first. 



