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 
attempt has been made to ascertain if the congenital ecaudate condition is, as a 
rule, transmitted to the immediate or subsequent offsprmg. 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. Ifa 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 tailin 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 
