358 EwART- Variation : Germinal and Environmental. 



have had a strange fascination for believers in the transmission doctrine. That 

 the tail is sometimes congenitally absent from animals whose ancestors have not 

 been subjected to docking is well known, but I am not aware that any recent 

 attemjit has been made to ascertain if the congenital ecaudate condition is, as a 

 rule, transmitted to the immediate or subsequent offs^Dring. There is a large 

 body of evidence that cutting off the tail in mice does not produce a tailless 

 breed, but I am not aware of any experiments of the kind with rabbits. 



About a year ago I found in a litter of rabbits one absolutely tailless, the 

 parents, grey half-wild rabbits, had tails of the usual length. Never having 

 heard of a "Manx" rabbit, the somewhat delicate sport was carefully reared, 

 and in due time mated with a member of his own litter, and with several 

 unrelated does. Altogether I bred, in this way, thirty-two young. In every one 

 of them the tail was perfectly normal, and it is also normal in all the members of 

 the following generations that have already appeared. If a rabbit born without 

 a tail — and hence, presumably, a prepotent " sport " — is incapable of producing 

 tailless descendants, it is unlikely that a rabbit which, whether by accident or 

 design, lost its tail after birth, would produce tailless offspring. 



Cropping the ears of dogs gives even more suggestive results than cutting off 

 the tail in mice. Terriers whose ancestors, for many generations, had their ears 

 cropped, instead of being nearly earless, have frequently abnormally large ears. 

 This is, doubtless, because cropping gave large- as well as small-eared individuals 

 a chance of leaving descendants. 



During the last four years I have crossed several different kinds of fancy 

 pigeons. The great lesson learned is, that it is difficult to combine the distinctive 

 characters of two well-marked breeds. When, e.g., a turbit with a pronounced 

 peak and frill is crossed with an ordinary pigeon, both peak and frill vanish, and 

 when a barb is crossed with an owl also decorated with a " frill," only plain birds 

 are ordinarily obtained. If characters (probably sports to start with) which 

 have prevailed for many generations are not readily transmitted except when two 

 like varieties are interbred, it seems to me improbable that a definite acquired 

 character — a trait that has never had a chance of being burned in — can by any 

 chance be transmitted. 



Breeders believe that shorthorns and other breeds of cattle are more docile, 

 mature earlier, and are more fertile than feral cattle. Fanciers believe tame rabbits, 

 pigeons, &c., are less timid and nervous than wild ones ; and in the same way 

 sportsmen imagine that pointers, setters, and retrievers work well because their 

 ancestors have been long subjected to careful training. In as far as our domestic 

 animals are docile, mature early, are highly fertile and easily trained, it is, I believe, 

 because our ancestors found it convenient, or most profitable, to select and breed 



