3 o8 



Mackenzie Delta on the north. All these sheep, including 

 those ranging parallel with the sheep of variable colors 

 in the Selwyn Rockies west of the divide, are pure white. 

 Joseph Keele, who made a special study of the distribu- 

 tion of sheep at the head of the Ross and Stewart Rivers, 

 and also of those east of the divide, asserts positively that 

 in those regions, owing to climatic conditions and areas 

 destitute of vegetation, sheep never cross the divide. It 

 is probable that further investigations along the divide, 

 both north and south, will show that sheep do not cross 

 anywhere except, perhaps, far to the north. This view 

 is supported by the fact that all sheep on the Mackenzie 

 side are white, which would not be the case were there 

 any intermingling. 



Where gray, brown, or black hairs occur on the sheep, 

 these hairs are within the pattern area emphasized in 

 Ovis stonei. The dark hairs are most persistent in the 

 tail and least persistent in the head and neck. Next 

 they are most persistent on the mid-dorsal line directly 

 above the tail; next on the back, ventral border extending 

 to the chest, and on the front sides of all the legs. When 

 I speak of sheep as pure white, it is never strictly true, 

 since a careful search will always reveal a few dark hairs 

 in the tail, and often above on the dorsal line, and more 

 rarely on the back. This is true even of the sheep along 

 the Arctic coast mountains, specimens of which I have 

 recently examined. 



Let us sum up the facts here presented. 



All the sheep of Alaska are uniformly pure white, 

 except occasional specimens between the Yukon and 



