48 THE SHEEP AND ITS COUSINS 



three surfaces is marked by a number of fine 

 parallel transverse wrinkles, which in old rams are 

 very closely approximated at the bases of the horns. 



In horns with this kind of curvature two types 

 may be recognised, in one of which the curve of 

 the spiral is considerably more open than is the 

 case in the other. As the horns of two rams from 

 Sardinia, the one presented by Mr. E. N. Buxton 

 and the other by Mr. Ford Barclay to the British 

 Museum, appear to conform to the close type, there 

 is a presumption that the open type may be char- 

 acteristic of the Corsican animal ; but evidence is 

 required as to whether the two types are really 

 distinctive of the two islands, or whether they both 

 occur together. 



This, however, is by no means the only dif- 

 ference in mouflon-horns ; the second kind of 

 variation being illustrated by the two heads shown 

 in plate i., which are rams shot by Mr. G. Stallard, 

 of Rugby, in Sardinia in 1902. In the first of 

 these (fig. I ) the horns have the normal curvature, 

 which results in their tips being widely sundered. 

 In the second head (fig. 2), on the other hand, the 

 horns curve backward behind the neck, and their 

 tips are consequently approximated. This is due 

 to a change in the direction of the upper part of the 

 curve, forming what is known as a mathematical 

 perversion, and due to the fact that whereas in the 

 one type the summit of the spiral is directed down- 



