210 Experimental Zoology 
pariah dog in India. It would seem that the result must be due to 
a single change of some sort in the germ that involves a correlated 
change in many parts at once. 
The Mauchamp breed of sheep originated also from a single 
individual ram that appeared in 1828. The wool is long and 
straight, not frizzled as in the merino. The ram and his imme- 
diate descendants showed also other new structural characters. 
The individuals of this breed are “‘of small size with large heads, 
long necks, narrow chests, and long flanks.” These peculiarities 
are removable by ‘‘judicious crosses and selection.” 
A monstrous breed of cattle exists in South America, the 
niata cattle, that must have originated from the introduced 
cattle; and to judge from its peculiarities, the breed must have 
appeared as a sport, although its actual origin is unknown. 
The upper lip is drawn back and the nostrils are situated high 
up. The exposed incisors give a peculiar appearance to these 
animals. The skull is much modified, the hind legs are shorter 
than usual, etc. The animals breed perfectly true to their kind. 
The short-horn cattle are also said to have originated from a 
sudden variation. 
A most interesting case is that of the Japan peacock, or 
black-shouldered kind. This form has appeared several times 
in England and differs so much from the ordinary forms that 
have given birth to it that it would be ranked as a different 
species were not its parentage known. ‘The birds breed true 
and have been known to replace in time the flock from which 
they arose. 
Several other cases are on record. Sports have been recorded 
among domesticated fowls, pigeons, horses, mice (rhinoceros 
mice), and frequently in plants of many kinds. They are known 
to have furnished the basis for several domesticated races. Un- 
fortunately exact information of the origin of races in this way 
would only be recorded when the saltation had been large in 
amount. When small, the change would be put down to fluctu- 
ating variations, especially by breeders who have had heretofore 
little interest in the difference between these two kinds of varia- 
