134 RODENTIA. 



row, and somewhat flattened tails; twelve molar teeth; and the 

 toes of the hind feet partially webbed. The species F. Zibethicus, 

 is the MUSK-RAT, called in Canada, MUSQUASH ; about the size 

 of a small rabbit, and of a reddish brown color ; sometimes black, 

 or black and white. This animal has four strong cutting teeth, 

 of which those in the under jaw are nearly an inch long ; in in- 

 stincts and disposition, it is similar to the Beaver. It receives its 

 name from its strong musky odor, deposited in glands, near the 

 origin of the tail. Its length varies considerably, but is generally 

 from eighteen to twenty inches, while the tail alone is from seven 

 to ten inches. The Musk rat frequents swamps and low, marshy 

 grounds ; and is specially fond of the calamus root, and of fresh 

 water muscles, or clams. Its utility consists in its fur, which is 

 soft and glossy, and used in hat making. The territorial range 

 of this animal is similar to that of the Beaver. 



5th FAMILY, PORCUPINES. 



Hystricidae, (Gr. "vcrr^l, hustrix, a porcupine ; 'Wr^-if, from 

 v$. hits, a hog; 0*, thrix, a bristle.) 



We have already contemplated in the Insectiuora, a group of 

 animals (Hedgehogs,) protected by a coat of spines. In the pres- 

 ent family, this spinpus defence is more strongly and decidedly 

 exhibited. The hollow tubes of the Porcupines are somewhat 

 like the quills of feathers. They usually terminate in a fine 

 point of hard enamel, but sometimes open at the end, as if cut 

 off at their greatest thickness. These quills seem to be a smooth, 

 glossy envelope of horn, with an inner pith or marrow of soft 

 texture, and pure white. "They grow from a bulbous root, 

 formed within a cell below the true skin, or cutis, and containing 

 also a portion of fat, in which the vessels supplying its pulp and 

 capsule, are imbedded. The capsules consist of three mem- 

 branes, of which the innermost secretes the horny envelope, while 

 the pulp supplies the pith of the spine." The spines vary in 

 size ; some are very long, slender and weak ; generally, they 

 are from four to eight inches in length, and very strong; thick in 

 the middle, and tapering to a point at the extremity. (See fig. on 

 the Chart.) They are less thickly set in the tail, which is short; 

 their place there is supplied by numerous, open, hollow quills, 

 raised on slender stalks, so as to vibrate with every movement. 

 When angry, the porcupine clashes these hollow quills together, 

 making a rustling noise, resembling; that of a rattlesnake. In his 

 undisturbed state, the spines lie down in regular order, with the 

 points all directed backwards; but when he is angry, they are 

 raised up by means of a peculiar muscular expansion under the 

 skin, and joined to it, which by its action, influences their elevation 



