142 THE BEAVER. 
layer of mud, laid on with marvellous smoothness, and carefully renewed 
every year. As this compost of mud, moss, and branches is congealed into 
a solid mass by the severe frosts of a North American winter, it forms a very 
sufficient defence against the attacks of the Beaver’s great enemy, the 
wolverene, and cannot readily be broken through, even with the help of iron 
tools. The precise manner in which the Beavers perform their various tasks 
is not easy to discern, as the animals work only in the dark. 
Around the lodges the Beavers excavate a rather large ditch, too deep to 
be entirely frozen, and into this ditch the various lodges open, so that the 
inhabitants can pass in or out 
without hindrance. This precaution 
is the more necessary, as they are 
poor pedestrians, and never travel 
by land as long as they can swim 
by water. Each lodge is inhabited 
by a small number of Beavers, 
whose beds are arranged against 
the wall, each bed being separate, 
and the centre of the chamber being 
left unoccupied. 
In order to secure a store of 
winter food, the Beavers take a 
vast number of small logs, and 
carefully fasten them under water 
in the close vicinity of their lodges. 
BEAVER.—(Castor Fiber.) When a Beaver feels hungry he 
dives to the store-heap, drags out 
a suitable log, carries it to a sheltered and dry spot, nibbles the bark away, 
and then either permits the stripped log to float down the stream, or applies 
it to the dam. 
We must now bestow a little time on the curious odoriferous substance 
which is called “castoreum” by the learned, and “bark-stone” by the 
trappers. This substance is secreted in two glandular sacs which are placed 
near the root of the tail, and gives out an extremely powerfu! odour. 
To the castoreum the trapper is mostly indebted for his success, for the 
Beavers are strangely attracted by this substance, and if their nostrils per- 
ceive its distant scent, the animals will sit upright, sniff about in every direc- 
tion, and absolutely squeal with excitement. Taking advantage of this 
curious propensity, the hunter always carries a supply of castoreum, in a 
closed vessel, and when he comes to a convenient spot for placing his trap, 
he sets the trap and then proceeds to manufacture his bait. This process is 
simple enough, consisting merely of taking a little twig of wood about nine 
inches long, chewing one end of it, and dipping it in the castoreum. The 
trap is now laid so as to be covered by about six inches of water, and the 
stick arranged so that its perfumed tip projects from tue water. Any Beaver 
which scents this bait will most certainly come to it, and will probably be 
captured in the trap. : 
THE ONDATRA, MUSQUASH, or MUSK Rat, is a native of Nortkern 
America, where it is found in various places above the rwentieth degree of 
north latitude. 
The colour of this animal is a dark brown on the upper portions of its 
body, tinged with a reddish hue upon its neck, ribs, and legs, the abdomen 
being ashy yrey; the tail is of the same dark hue as the body. In total 
length it rather exceeds two feet, of which measurement the tail occupies 
about ten inches, The incisor teeth are bright yellow, and the naiis are 
