THE CROSSING, &C, OF PIGEONS AND FOWLS. 2T3 



" In order," he says (p. 283, Vol. ii, Animals and 

 Plants, &c), "that selection should produce any result, 

 it is manifest that the crossing of distinct races, must 

 be prevented. * * Although free crossing is a 

 danger on the one side, which every one can see, too 

 close-interbreeding is a hidden danger, on the other 

 side." 



In other words, crossing "must be prevented," be- 

 cause such a process would prejudice the special ex- 

 cellence of the breed, and imperil the predominance of 

 the one part valued, by the development of the other 

 parts. " Serious defects in parts," and " in the mutual 

 relation of the parts," are what constitute the excellence 

 of the birds, in fanciers' eyes; for the pronounced 

 and exclusive development of some one peculiarity 

 is what makes each variety so unique and valuable. 



On the other hand, "too close-interbreeding is a 

 hidden danger," because it is the Nemesis attending, 

 the suppression of those other parts, which are sup- 

 pressed in order to throw the given peculiarity into 

 prominence. 



To put the whole philosophy of Darwin's double 

 warning, in a nutshell : All the characters are neces- 

 sary to be developed, in each individual; but, if the 

 fancier desires individuals, with one character only well- 

 developed, and with the other characters reduced or 

 suppressed, he must take care not to cross, for that will 

 be aiding the development of the characters which it is 

 desirable should be suppressed; and on the other hand, 

 he must look out for the evils which are visited upon 

 the individuals, for having those other parts reduced, 



or suppressed. 

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