112 PRINCIPLES AND PRACTICE OF BREEDING. 



and considerably less uniform.. In these last, he has 

 encountered a force of hereditary transmission equal to his 

 own, except in so far as he is aided by superior power of sex. 

 Persons who buy rams, generally buy from flocks better 

 bred than their own, and hence is witnessed that assimilation 

 of the progeny to the sire, and consequently that improve- 

 ment, which is by some referred exclusively to sex, and by 

 others to some inherent property to "mark" his oiFspring 

 supposed to be peculiar to the sire. This hypothesis is not 

 overthrown by the notorious fact that rams from the same 

 flock exhibit the power of hereditary transmission in 

 essentially diflTerent degrees, any more than is the hypothesis 

 of the superior influence of the male sex overthrown by the 

 same fact. Every flock has separate and better strains of 

 blood within itself — even where all are descended from the 

 same stock. Not only better males occasionally present 

 themselves, but also better females. If the latter are found 

 to transmit their own properties in a special degree to their 

 ofispring, they are highly prized and carefully reserved from 

 all sales. Each female descendant is prized and reserved in 

 the same way, and a sub-family is thus created. A touch of 

 in-and-in breeding (by using a ram from the same sub-family 

 on his relatives, as well as on the rest of the flock,) frequently 

 aids to confer an identity on this little group of sheep which 

 preserves itself for generations — as long as the flock is kept 

 together. I am not acquainted with a celebrated breeding 

 flock which has not within it several such recognized groups 

 or sub- families of difierent value, but all better than the 

 body of the flock. This explains how rams of the same blood 

 and flock, and perhaps general appearance, may difier materi- 

 ally in their qualities as sires, without imagining the existence 

 of an independent faculty based on no physical properties. 

 There is still another circumstance which affects the 

 power of hereditary transmission, viz., vigor, — general 

 physical vigor, and also special sexual vigor. A very strong, 

 powerfully developed ram, full of power and vital energy — 

 and full of untiring sexual ardor — wUl get . stronger and 

 better lambs and impress his own qualities on them more 

 strongly than an ill, or feeble, or flaccid ram, with naturally 

 weak or exhausted sexual powers. The ram should be 

 essentially masculine in every organ and function.* He 



* Large testicles, and large, firm spermatic cords connecting these with the body, 

 are regarded as indications of sexnal vigor in the ram. The capacity to " hear heavy 

 feed ^' has also much to do with a ram's endurance in this particular. 



