MAMMALIA. 117 
spring time; yet their flesh is eaten by the Indians, and when it is fat they prize 
it for atime, but are said to tire of it soon—it somewhat resembles flabby pork. 
~ Tn latitude 55°, the Musquash has three litters in the course of the summer, and, 
from three to seven young at a litter. They begin to breed before they attain 
their fall growth. The districts in which they are most abundant are subject to 
inundations, which, covering all the low grounds, leave no resting places for these 
animals, and destroy great numbers; in severe winters, also, they are sometimes 
almost extirpated from certain parts of the country by the freezing up of the 
swamps, which they inhabit. ‘In such cases, being deprived of their usual food, 
they are driven by famine to destroy each other. They are likewise subject at 
uncertain intervals to a great mortality from some unknown cause. Their great 
fecundity, however, enables them to recover these losses in a very few years, 
although the deaths are at times so numerous, that a fur-post, where the Musquash 
is the principal return, is not unfrequently abandoned until they have recruited. _ 
_ The southern limit of the range of the Musquash may be stated to be some- 
where about latitude 30°. Bartram informs us, that they exist in the northern parts 
of Georgia and Florida; and we have ascertained that they extend northwards 
nearly to the mouth of the Mackenzie, in latitude 69°. Their favourite abodes 
are small grassy lakes or swamps, or the grassy borders of slow-flowing streams 
where there is a muddy bottom. They feed chiefly on vegetable matters; and 
in northern districts principally on the roots and tender shoots of the bulrush and 
reed-mace, and on the leaves of various carices and aquatic grasses. ‘The sweet- 
flag (acorus calumus), of whose roots, according to Pennant, they are very fond, 
does not grow to the northward of Lake Winipeg. In the summer, they frequent 
rivers, for the purpose it is said of feeding upon the fresh-water mussels (Unio). 
We often saw small collections of mussel-shells on the banks of the larger rivers, 
which we were told had been left by them. 
In the autumn, before the shallow lakes and swamps freeze over, the Musquash 
builds its house of mud, giving it a conical form, and a sufficient base to raise 
the chamber above the level of the water. The chosen spot is generally amongst 
long grass, which is incorporated with the walls of the house, from the mud 
being deposited amongst it, but the animal does not appear to make any kind of 
composition or mortar by tempering the mud and grass together. There is, 
however, a dry bed of grass deposited in the chamber. The entrance is under 
water. When ice forms over the surface of the swamp, the Musquash makes 
breathing holes through it, and protects them from the frost by a covering of 
mud. In severe winters, however, these holes freeze up, in spite of their cover- 
