THE PAKNASSIAN SHEEP. 
261 
sist, to quote the definitions of M. Cuvier, in the Sheep 
having " their horns directed backwards and returning 
more or less forwards in a spiral manner, with a gene- 
rally convex line of profile, and no beard;" while the 
Goats have " their horns directed upwards and back- 
wards, their chins generally decorated with a long 
beard, and their line of profile almost always concave." 
To these differences some writers have added the woolly 
fleeces of the Sheep, and the hairy coverings of the 
Goats ; but all the wild Sheep, and even some of the 
domesticated races, are clothed with long hair, and 
many of the cultivated varieties of Goat, those of Thibet 
and Angora for example, are remarkable for the length 
and fineness of their wool. The horns too vary so ex- 
tensively in both cases, and the convexity of the line of 
profile is subject to so many modifications, as to render 
the distinctions drawn from these characters of no prac- 
tical value. On the presence or absence of the beard it 
would be absurd to dwell as offering the semblance of a 
generic character, to distinguish between animals which 
actually produce together a mixed breed capable of 
continuing their race. From all these considerations 
we are led to infer that the Sheep and the Goat cannot 
properly be said to form the types of separate genera. 
With regard to the second point, the specific distinc- 
tion between the different races of Sheep still met with 
in a state of nature, we have yet formed no decided 
opinion. It is certainly by no means easy to admit so 
marked an exception to the general laws that regulate 
the geographical distribution of animals, as would be 
involved in the supposition that the same species is 
found in isolated regions so widely differing from each 
other as the North of Africa and the South of Europe, 
the great chain of the Caucasus, the wilds of Tartary 
and Siberia, and the Rocky Mountains of North Ame- 
