ON BREEDING. 
195 
The differences in the colour of horses have been very con¬ 
fidently ascribed to domestication . Animals living in a state of 
nature have not sustained any variation in their colour; but when 
domesticated, they have undergone such a variety of alterations 
as to render it impossible to trace back the stock from which 
they originated. Alterations of colour daily occur among all 
domestic animals : the rabbit, cat, pig, and dog, are striking in¬ 
stances. The greatest mutation in the colour of horses are the 
tiger, the leopard, the piebald, and the strawberry colours. 
Leopard and tiger-coloured horses are common among the Mon- 
guls, in Asiatic Russia. The piebalds are very plentiful in 
China. Similar varieties have been observed among mankind : 
individuals are sometimes spotted with different colours; blacks 
are sometimes marked with patches of white, whose parents were 
perfectly black. 
The milk-white and cream-coloured horses are very analogous 
to the human Albinos in the whiteness of their skins and other 
integuments. White haired horses, like white haired persons, 
are irritable and weak, yet they were highly esteemed by the 
ancients, who believed that they excelled all others in swiftness. 
“ Qui candore nives anteirunt cursibus amas.” 
r , 
Pure white or leucaetheapic horses are very rare animals; 
the common white horses are those that are changed to white 
from grey by age. An enquiry might reasonably be made, how 
we are able to account for so many different colours proceeding 
from one common stock. Domestication has been assigned as 
the principal cause; for we know that the domestic state is con¬ 
tinually producing deviations from the ordinary course of nature ; 
yet we cannot tell how or in what manner these varieties are 
produced. 
The various colours must be considered as accidental varieties, 
and the union of the same colours makes these varieties here¬ 
ditary ; for it is a well-known fact, that if animals marked by 
certain native peculiarities generate, and their offspring are again 
and again matched with similar kinds, that any variety might be 
fixed as a permanent breed. The union of the different breeds 
has a great effect in altering the colour,‘conformation, and other 
properties of the offspring, and is thereby used with considerable 
benefit in meliorating the different breeds of domestic animals. 
Various causes may be assigned for these accidental varie¬ 
ties; they are sometimes produced by mental impressions on 
the part of the mother*. The Earl of Morton bred from a male 
quagga and a young chesnut mare; the result was a female 
* Vide Philosophical Transactions. 
