Wright : Bates' Duchess Cattle 



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RELATIONSHIP OF THE DUCHESS COWS TO FAVORITE 



8 



Figure 25. The degrees of relationship to the bull Favourite of the Duchesses (solid 

 line), of their sires (broken line), and of their dams (dotted line). For eight generations 

 Bates maintained a closer resemblance to Favourite than between parent and offspring (50 

 per cent) in a stock not inbred. 



a "pure" Duchess strain after Bates' 

 death. On the whole it must be con- 

 ceded that Bates managed to maintain 

 a happy medium with respect to the 

 plasticity of his stock. 



Let us compare a little more closely 

 the methods followed by Bates and 

 those suggested by Mendelian theory. 

 In combining inbreeding and selection 

 there are several methods which may 

 logically be followed depending on the 

 genetic complexity of the characters, 

 the importance of environmental varia- 

 tion and such factors as the extent of 

 the operations and the amount of risk- 

 to be undertaken. 



The first step in any case should be 

 selection of a vigorous foundation, ap- 

 proaching as closely as possible to the 



desired type. This was the step taken 

 by the Collings in purchasing the 

 original Duchess, Favourite Cow, the 

 bull Hubback, and so forth. 



With such a foundation stock, one 

 might practice the most intensive in- 

 breeding in a large number of distinct 

 lines, knowing that most lines would 

 inevitably deteriorate greatly, but trust- 

 ing that a few would be found in 

 which desirable qualities would become 

 fixed, and in which the deterioration in 

 any vital respect would be so slight 

 that they could be maintained success- 

 fully. By crossing such lines which 

 have withstood this acid test of in- 

 breeding, one might reasonably hope to 

 recover more than the original vigor 

 and retain those characters which had 



