THE SHESP. 



287 



The domestic sheep {Ovis aries) is not a natural species, 

 but an association of races whose specific origin is obscure. 

 Some authors regard tlie turf sheep of the Stone Age of 

 Europe as the ancestor of the domestic sheep, since forms 



Fig. 317.— Rocky Mountain Sheep or Big-Hom. 



like it are now living in the Shetland Islands and in Wales. 

 It was of small size, with slender legs, and ei'ect, short 

 horns. This sheep was supplanted by a curved, large- 

 horned form, the modern domestic sheep. This latter 



