Mr. Collie on the Natural History of the Kangaroo. 239 
had been caught with its little young in the sac at the teat. This young 
one, which has not obviously increased since, is of nearly the size of the 
last and half the middle joint of one’s little finger; its integuments of a 
flesh colour, and so transparent as to permit the higher coloured vessels 
and viscera to shine through them; whilst all its extremities seem com- 
pletely formed, and its muscular power is fully testified by its evident 
efforts in sucking, during which it puts every part of its body into action. 
According to the testimony of the person who preserved the mother with 
this little one for me, the latter by no means passes the whole of its time 
with the lacteal papilla in its mouth, but has been remarked, more than 
once, without having holdof it. It has even been wholly removed from 
the sac to the person’s hand, and has always attached itself anew to the 
teat. Yesterday, on again looking at it, I gently pressed, with the tip of 
my finger, the head of the little one away from the teat of which it 
had hold, and continued pressing a little more strongly for the space of a 
minute altogether, when the teat that had been stretched to more than an 
inch, came out of the young one’s mouth, and shewed a small circular 
enlargement at its tip, well adapting it for being retained by the mouth of 
the sucker. The opening of the mouth seemed closed in on both sides, and 
only sufficiently open in front to admit the slender papilla. After this I 
placed the extremity of the teat close to the mouth of the young, and held 
it there for a short time without perceiving any decided effort to get hold 
of it anew, when I allowed the sac to close and put the mother into her 
place of security. An hour afterwards the young was observed still 
unattached, but in about two hours ithad hold of the teat and was 
actively employed sucking. On examining the sac of another Kangaroo 
I found a still smaller young one in it than the preceding. This one is 
about one half larger than the body of the common Wasp, (Vespa vul- 
garis). Its extremities, even to its toes, are evidently developed, and its 
skin is still more transparent than the before mentioned. The papilla to 
which it is attached, and from which its body hangs suspended without any 
other support than the hold which it has of the papilla, (a position into which 
I purposely placed it,) is, like the young, delicate, smooth and purplish, 
exhibiting a high degree of vascularity, and is about ,7; of an inch long. 
The gland, however, at its base is very little enlarged, so little indeed as to 
be scarcely perceptible ; whilst that at the base of another papilla which 
