i8o 
RODENTS. 
One of the best known of the many species is the restless cavy 
Restless Ca/vy ^ ** 
(Cavia porcellus ) of Uruguay and Brazil, which measures rather 
more than 10 inches in length, and attains a weight of about a pound. The 
colour of the rather long and coarse fur is greyish brown; and the incisor teeth 
are white. This species is common in certain districts in the neighbourhood 
of the Rio de la Plata, where it is known by the name of aperea. According to 
Darwin, it is occasionally found on the sandhills or the hedges of aloes and 
cactuses; but its more usual and favourite haunts are marshy spots covered 
with aquatic plants. In the latter situations it lives among the shelter of the 
vegetation, but in sandy districts it excavates burrows. It usually comes forth 
to feed in the evenings and mornings; but in cloudy weather may sometimes 
be seen abroad at all hours. In Paraguay Dr. Rengger states that it is 
invariably found in moist situations on the borders of the forest, where it 
lives in societies comprising from six to fifteen individuals, among the dense 
masses of bromelia. Here it makes regular beaten paths, and never wanders 
far afield. It breeds but once a year, producing only one or two young. Cutler’s 
cavy (0. cutleri), from Peru, is a rather smaller species, distinguished by the 
general black hue of the fur, although the flanks and more especially the under¬ 
parts tend to brown. 
Much discussion has arisen as to the origin of the domestic 
guinea-pig. It was long considered to have been derived from the 
restless cavy; although several writers pointed out that from its aversion to wet 
and cold such an origin was improbable. From the researches of Dr. Nehring of 
Berlin, it appears, however, that the real ancestor of the domestic breed is the 
above-mentioned Cutler’s cavy. It has been ascertained that the latter species 
was domesticated by the Incas of Peru, from whence it w r as carried to Colombia 
and Ecuador; while, on the other hand, no cavy was ever domesticated in Brazil. 
The domesticated cavies of the Incas were either uniformly white or reddish brown, 
or a mixture of those two colours. In Europe guinea-pigs are generally either 
white or white marked with yellow and black. Occasionally, however, they may 
be white marked with pale yellow, and in such cases they invariably have pink 
eyes. Sometimes, again, they may be marked with brownish black, mouse-colour, 
or yellowish grey; while in certain cases the black may be replaced by ashy 
grey, when the eyes are pink. Of late years a breed has been formed with 
exceedingly long coarse hair, and of larger size than ordinary. Guinea-pigs 
were introduced into Europe by the Dutch during the 16th century, shortly 
after the discovery of America; the name being probably a corruption of 
Guiana-pig. From their pretty appearance and ways, as well as the ease with 
which they are kept and the rapidity with which they multiply, guinea-pigs 
have always been favourite pets with children; although it must be confessed 
that from their stupidity and want of affection they cannot be regarded as very 
interesting creatures. When, however, a number of these rodents are kept 
together, they certainly form a pretty sight; and the manner in which they 
follow one another round and round their place of confinement in unbroken order 
is very remarkable. In some respects they resemble rabbits in their habits, while 
in others they are more like mice. Their pace is by no means swift and consists. 
