78 J GEOLOGICAL SURVEY OF CANADA. 



grass and moss. At the time of birth the cubs are the size of a 

 squirrel, black in color, quite helpless, with closed eyes. They 

 are suckled for five months, the male assists in rearing the young. 



Thalassarctos maritimus, Linn. White Bear. 

 Coition, which is dog-like, takes place about the middle of April, and 

 the young, from one to three in number, are born in holes under 

 rocks lined with brush, grass, and moss, towards the end of October. 

 At time of birth they are the size of a large rat, white in color, 

 helpless, and with closed eyes. They are suckled for five months, 

 the male assisting in rearing them. 



Fiber sibetMcus, L. Muskrat. 



This animal mates about the middle of May, coition being cat-like, 

 and the young, from one to six in number, are born about the 

 middle of June. At time of birth they are the size of a small 

 mouse, light brown in color, helpless, with closed eyes. The nest 

 is built in a house or lodge, made of sticks and mud, in shallow 

 ponds or quiet streams, and is lined with grass and moss. The 

 female suckles the young for three weeks, and is assisted by the 

 male in rearing them. The muskrat breeds twice subsequent to 

 the first birth during the summer. 



Erethizon dorsatus. L. Canada Porcupine. 



Coition, which is cat-like, takes place about 1st October, and the 

 young one is born unsheltered at the end of April. When born 

 it is the size of a small rat, black in color, active, with open 

 eyes. The female suckles it for two weeks, and is unassisted by 

 the male in rearing it. 



Castor fiber, L. Beaver. 



At the end of February coition, which is cat-like, takes place, and the 

 young, from one to nine in number, are born about the 1st June, 

 in a house lined with brush and grass. They are then the size of 

 a rat, light brown in color, helpless, with closed eyes. The female 

 suckles the young for six weeks, and is assisted by the male in 

 rearing them. 



Arctomys monax, L. Woodchuck, Wenusk. 



Coition, which is cat-like, takes place about the middle of October, 

 and the young, from one to ten in number are born about the 1st 

 May. At time of birth they are the size of a large mouse, yellow- 



