IN-AND-IN BREEDING. 161 



If he presented any characters that were not to be 

 reconciled with the improved type of his breed as 

 in the fancied resemblance to " a Holderriess or Tees- 

 water bull " it would certainly be more reasonable 

 to refer them to the atavic transmission of some re- 

 mote cross than to accidental variation. 



In attempts to ingraft a new or modified char- 

 acter upon those representing a family type, without 

 destroying the specific characters of the family, close 

 breeding within the limits of the family must be prac- 

 tised to prevent too wide a divergence in the domi- 

 nant characters. 



Diagram 6 may be studied with profit, as it shows 

 the skillful manner in which the blood of the light- 

 colored ewe was infused into the flock of Mr. Ham- 

 mond, to tone down the tendency to the production 

 of excessive yolk without destroying the other desir- 

 able qualities of the descendants of old Black, and the 

 first choice of old ewes and first choice of ewe-lambs. 



From this general examination of (the practice of 

 in-and-in breeding by the most celebrated breeders, it 

 appears that they have made use of it to secure uni- 

 formity in their breeding-stock, to fix the slight vari- 

 ations that they sought in the process of improvement 

 and blend them with the best original characters, and 

 to secure the important quality of prepotency in the 

 males that they made use of to " improve " the aver- 

 age characters of their stock. 



We will now proceed to a consideration of the 

 alleged ^influence of in-and-in breeding in producing 

 delicacy of constitution, lack of fecundity, and a ten- 

 dency to disease and abnormal peculiarities. It is, 



