SECTION I 



TYPES COMMON TO BOTH HEMISPHERES 



THE ROCKY MOUNTAIN BIGHORN SHEEP 



(Ovis ca/hhicnsis) 

 (Plate I. Fig. i) 



None of the species of wild sheep have anything hke a circumpolar 

 distribution, but the nearest approximation to such a wide range is made 

 by the so-called " bighorn," of which the typical locality is the Rocky 

 Mountains of America. Bighorns, whether (as here) regarded as local 

 races of one variable form or as distinct species, are all very closely related 

 indeed, and evidently modifications of one and the same type of animal. 

 And as one modification of this type is met with in Kamchatka and the 

 neighbouring districts of North-Eastern Asia, they are clearly entitled to 

 occupy a place in the present section. 



For the character by which the wild sheep are distinguished from 

 their near relatives the wild goats, and likewise from other ruminants, the 

 reader may be referred to another volume of the present series.^ It may, 

 however, be mentioned that since the publication of that volume it has 

 been shown by Mr. G. Wherry '" that the majority of the sheep may be 

 distinguished from the goats by the circumstance that the right horn forms 



1 H'ilJ Oxen, S/:eep, and Goats of All Lands. - Nature, vol. Ixiii. p. 252 (1901). 



