INDIVIDUAL VARIATION. 219 



skins and heads of four sheep, amongst which 

 were those of the two young males he had spied 

 on the previous day, the other two being those 

 of two okl ewes. These four skins differed very 

 much in coloration, those of one of the ewes 

 and of the younger of the two males being dark 

 grey all over the back and sides, whilst those of 

 the other ewe and the older male were nearly 

 white, though they both had a distinct tinge of 

 grey on the back. They all had snow-white 

 heads and necks and rumps and black tails, 

 but in the two darker specimens a black line 

 ran from the tail up the median line of the body 

 to the grey of the back. 



The coloration of these sheep is, I think, 

 very interesting, as it shows that in one small 

 flock great individual variation may be found. 

 None of the sheep found on the mountain ranges 

 near the Macmillan River are, I believe, pure 

 white all over, that is, typical specimens of Ovis 

 dalli ; but most of them look quite white at a 

 distance, and have only a light sprinkling of 

 greyish hairs on the back. Others again are 

 of a dark grey colour on the backs and sides, 



