THE VIRGINIAN OPOSSUM. 269 • 
and the legs are of a deep chestnut brown. The 
whiskers are long, partly white and partly reddish ; 
the extremity of the nose flesh-coloured with a tinge 
of yellow ; and the ears generally black at the base 
and yellowish at the tip. The tail is considerably 
shortei than the body ; its base is covered by long- 
hairs, but the greater part of its length is only scantily 
supplied with short bristles which emerge from between 
the small whitish scales by which it is protected. The 
young are of a purer white than the full-grown animal. 
This is the only species, with the exception of the 
Mexican CayopoUin, that inhabits North America. It 
is extremely abundant in the North of Mexico, and 
throughout nearly the whole of the United States ; and 
has consequently formed the subject of most of the 
experiments that have been instituted for the solution 
of the yet incompletely penetrated mystery of the 
breeding and gestation of marsupial animals. Little is 
known concerning the latter point beyond the curious 
facts that the almost shapeless young, of scarcely more 
than a grain in weight, and generally about twelve in 
number, are found at first inseparably attached to the 
teats within the pouch ; that as they increase in size 
the teats become proportionally enlarged and are pro- 
longed into the stomachs of the young; that after a 
certain number of days, having attained about the size 
of a mouse, and all their parts being completely foraied, 
they abandon the teats, to which they thenceforward 
only return like other suckling animals to satisfy the 
cravings of their appetites, occasionally quitting the 
pouch itself, but still flying to it for shelter on the 
slightest alarm ; and that they finally abandon it also 
at the end of about fifty days from the period when 
they were first deposited within it. In what manner 
this deposition takes place, and what is the object that 
