THE NATURALIST'S VISION 349 



the rock-pigeon of Europe; but what definite 

 steps were taken, or what methods were pursued 

 to obtain such divergent forms as fantails, tum- 

 blers, and carriers is not of record. Similarly, 

 canary-birds have common progenitors attributed 

 to them, so that their departure from the original 

 type is very great, the breeds being as defined and 

 marked as are the breeds of pigeons. What steps 

 the breeders and fanciers took to achieve such 

 ends is very obscure. It would seem that there 

 is an underlying reason for all this. The success- 

 ful breeder was loath to make public the methods 

 pursued ; because as long as he had a patent on a 

 given kind of horse or bird, desirable in a com- 

 mercial way, he was so much better off than the 

 other breeders ; and therefore, while many treatises 

 have been written, and much has been discussed 

 by breeders, more has been concealed, or at least 

 allowed to go unrecorded. 



So far the results of variation that breeders 

 have obtained are represented by what are known 

 as thoroughbreds ; forms of life presenting at 

 least external characters as definite as those upon 

 which wild species are based. The adventitious 

 aid of man appears to be essential, however, to the 

 prolongation of any of the so-called thoroughbred 

 types of domesticated animals, whether bird or 

 beast. The moment that man's efforts are relaxed, 

 and commingling of the various thoroughbred 



