Natural History of the Hudson's Bay Territories. 23 
small and weak, and not provided with a web ; the claws are 
strong, and well adapted for digging, but not equal to those 
of the hind feet. The hind feet and legs are enormously 
strong, the fingers united by a strong broad web, the claws 
excessively developed, and each in the form of a strong gouge. 
The combination of machinery in the fore and hind legs and 
feet thus corresponds with what we know of the habits of the 
animal so far as that can be observed ; and the structure of 
that portion whose working is difiicult to be observed in action, 
or has not been noticed sufficiently, shows what its real work- 
ing is. Those who have observed the animal in its native 
haunts, tell us that it uses the fore paws for carrying the mud 
and stones used in its constructions, and that it carries this 
stuff between them and its breast, which quite corresponds 
with their attitude in my dead specimen. It no doubt uses 
the fore paws for other purposes, as digging, swimming, and 
walking (for nature seldom or never creates an organ merely to 
fulfil one purpose). As clearly, the hind paws are much used in 
digging, but most in swimming ; — the powerful hind leg, enor- 
mous web foot, and strong claws, would prove this although no 
one had ever seen the animal using them. Combine these 
different actions of the fore and hind feet together and see what 
would be the result. Suppose the animal swimming across its 
pond or river with a burden of heavy materials clasped to its 
breast by its fore paws, and powerfully propelled by its hind legs, 
and that it had no tail or only a common tail — what must inevi- 
tably be the consequence ? The hind feet would propel the animal 
rapidly enough — no doubt about that — but where to 1 — why, to 
the bottom, for, being overloaded in front, it would be top heavy, 
and its head becoming directed obliquely downwards the more 
violent the exertions of the hind feet, the sooner it would reach 
the bottom, and the deeper its head would be buried in the mud. 
That this is the necessary and inevitable consequence of the 
want of the action of the fore paws, will be evident to every one 
if they will merely fancy what would be the result of their try- 
ing to swim with their arms folded ; of course, if there is not 
only the inaction or abeyance of the fore arms to be conquered, 
but also the weight of a load of mud or stones to be counteracted, 
a counterpoising lever of more than ordinary power will be ne- 
