296 THE SHEEP AND ITS COUSINS 



come certain specimens killed near the head of the 

 Klondyke River, some of which have a decided 

 grey mantle and dark stripes down the legs, like 

 fannini, although the head and neck are pure 

 white. Somewhat further south, in the Stewart 

 River district, the bighorns seem to be rather 

 darker on the average, being, except for the white 

 head and neck, almost like the typical stonei. On 

 the Upper Macmillan River the sheep are in 

 general of this dark type, although a few are 

 scarcely distinguishable from typical dalli. From 

 the white-headed dark sheep there is but a step 

 to the typical black stonei, the change from the 

 white to the black type being thus practically 

 complete, and corresponding to the changes in 

 environment." 



According to Mr. Sheldon, who wrote several 

 years later, in Alaska, from the Arctic coast south 

 to latitude 60°, and in Yukon Territory and north- 

 eastward in the Mackenzie Mountains to about 

 latitude 62°, the sheep are mostly pure white, except 

 in the Tanana Hills south of the Yukon River, 

 where the white is varied with a few black hairs 

 and slight indications of the colour-pattern of the 

 fannini type ; in British Columbia south of the 

 Stikine River the sheep are uniformly black ; but 

 over an intervening region of from approximately 

 six hundred and fifty miles north and about one 

 hundred and fifty to two hundred miles east and 



