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 supei'ior 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 offspring 



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 different 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 bettor 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 



offspring, they are highly prized and carefully reserved fr,om 



all sales. Each female descendant is prized and reserved in 



the same way, and a sub-family is thus created. Avouch 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 different 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 differ 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 Avill 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, 



m. The capacit 

 n this particular. 



, , 



are regarded as indications of sexual vigor in the ram. The capacity to " bear heavy 

 feed" has also much to do with a ram's endurance i 



