286 MOSTLY MAMMALS 



to relieve the animal of the inconvenience of pressure upon 

 the neck." 



Precisely the same description, inclusive of the sawing off 

 of the top of the amalgamated horns, would apply to the 

 two skulls of this breed in the British Museum, 



In the case of the many-horned breed of sheep it would 

 seem that the redundancy in horn-development is more 

 probably a disadvantage than a benefit to the animals in 

 which it occurs. And if, as seems to be the case, the 

 amalgamated horn in the unicorn-sheep tends to run into 

 the neck of the owner so as to necessitate the amputation 

 of the tip, the abnormaUty is altogether harmful ; so that 

 if it occurred in a state of nature it would probably soon 

 disappear. 



This amalgamation of the horns in the unicorn-sheep 

 presents a curious analogy to the so-called solid-hoofed pigs, 

 which have been known from a very early period. " From 

 the time of Aristotle to the present time," wrote Darwin, 

 " solid-hoofed swine have occasionally been observed in 

 various parts of the world. Although this peculiarity is 

 strongly inherited, it is hardly probable that all the animals 

 with solid hoofs have descended from the same parents ; it is 

 more probable that the same peculiarity has reappeared at 

 various times and places." The peculiarity is produced by 

 the welding together of the middle pair of hoofs into a single 

 large hoof. 



Although we may at present be unable to explain the 

 curious variations displayed by different organs among 

 animals under domestication, this is surely no reason why 

 we should refuse to study them at all. 



