PEINCIPLES AND PEACTICB OF BBEEDI17G. Ill 



The ram is generally " higher bred " than the ewes, even 

 in full blood flocks. As pure blood is only separate family 

 blood which has been kept distinct until it transmits but 

 one set of family characteristics, so higher blood is produced 

 by the selection of pure blood animals of choicer qualities 

 and breeding them together separate and distinct from all 

 others, until they form a smaller improved sub-family, alike 

 possessing a permanent hereditary character. The thin-chined, 

 low fore-ended, roach - backed, black -faced sheep which 

 formerly depastured the downs of Sussex, were of as pure 

 blood as the superb South Downs which Mr. Ellman created 

 out of them — but they were not so highly or well br6d. 

 The improved South Down ram of to-day does not transmit 

 the same properties to his progeny which the unimproved 

 animal of eighty years ago did. He not only transmits 

 better ones, but he transmits them with more force and 

 uniformity. This last is occasioned by two circumstances. 

 The restriction of the sub -family for a number of generations 

 to one fixed standard, gives greater force of hereditary 

 transmission to the fewer properties — that is, fewer in 

 kind — which that standard admits of, because by that law 

 on which "blood" or "species" rests, the oftener the same 

 quality is reproduced, the stronger becomes its tendency to 

 continued reproduction. The improved South Down breeds, 

 so to speak, to one uniform pattern. The unimproved one 

 breeds to a dozen different varieties of a family pattern. 

 The second circumstance which gives a stronger power of strict 

 hereditary transmission to the high-bred animal, consists (after 

 the improved family becomes thoroughly established) in the re- 

 striction placed on the limits of breeding back. The unimproved 

 South Down could breed back to fifty difierent ancestors, all 

 differing quite widely ; the improved one, unless he casually 

 goes far back of the ordinary limits of Isreeding back, can 

 only breed back to ancestors of very close resemblance. 



If the pure blood ram is put to grade ewes of different 

 and no determinate blood, his strong power of hereditary 

 transmission is encountered by no corresponding power on 

 the other side, and the. resemblance of the progeny to 

 himself is unexpectedly striking, considering that they are 

 but half of the same breed. If put to full blood ewes of 

 his own breed, but lower bred than himself, the resemblance 

 to himself is much less marked, though it is still very 

 perceptible. If put to ewes of the same breed and as high 

 bred as himself, the resemblance to himself is still fainter 



