HERITABLE DIFFERENCES 49 



It occurred to this hard-headed Yankee that it would 

 be much easier to get together a flock of short, bow- 

 legged sheep, unable to negotiate anything but a low 

 hurdle, than to labor hard at building high fences. 

 So it came about that this mutating lamb, in the hands 

 of a man who appreciated labor-saving devices, became 

 the ancestor of the Ancon breed of sheep. Later on 

 this breed gave place in public favor to another mu- 

 tant, the Merino, which produces a superior grade of 

 wool. 



Some mutations, however, that may be selected and 

 maintained by man are unlikely to succeed in nature 

 when left to themselves. Albino animals, for example, 

 are so handicapped by defective eye-sight that they 

 have a hard struggle in the wild condition. Albino 

 rats set free by Dr. Hatai a few years ago upon Goose 

 Island, a small uninhabited bit of land in Long Island 

 Sound, all succumbed to the native rats in a short 

 time. 



Hornless cattle suffer fewer injuries from one an- 

 other than horned cattle. It has consequently become 

 quite a general practice among farmers to "dehorn" 

 their stock surgically. It is an obvious advantage to 

 have cattle born hornless, and many breeds having 

 this character are now established. In 1889 a mutant 

 among horned stock appeared at Atchison, Kansas, 

 in the form of a hornless Hereford. From this mutant 

 has descended the well-established race of polled Here- 

 ford cattle, constituting a bovine aristocracy with 

 registry books and blue blood all their own. 



Taillessness in cats, dogs and poultry, as well as 



