4.26 THE CAUSES OF THE XI 
however, tell you that it is quite different. The 
wild Horse of Asia is said to be of a dun colour, 
with a largish head, and a great many other pe- 
culiarities; while the best authorities on the wild 
Horses of South America tell you that there is no 
similarity between their wild Horses and those of 
Asia Minor; the cut of their heads is very differ- — 
ent, and they are commonly chestnut or bay- 
coloured. It is quite clear, therefore, that as by 
these facts there ought to have been two primitive 
stocks, they go for nothing in support of the as- 
sumption that races recur to one primitive stock, 
and so far as this evidence is concerned, it falls to 
the ground. 
Suppose for a moment that it were so, and 
that domesticated races, when turned wild, did 
return to some common condition, I cannot see 
that this would prove much more than that simi- 
lar conditions are likely to produce similar results ; 
and that when you take back domesticated ani- 
mals into what we call natural conditions, you do 
exactly the same thing as if you carefully undid. 
all the work you had gone through, for the pur- 
pose of bringing the animal from its wild to its 
domesticated state. I do not see anything very 
wonderful in the fact, if it took all that trouble to 
get it from a wild state, that it should go back in- 
to its original state as soon as you removed the 
conditions which produced the variation to the 
domesticated form. There is an important fact, 
