114 The Ottawa Naturalist. [January 



over the large orange-colored, chisel-like teeth. The short thick legs 

 terminate in small horny-soled feet armed with long black claws well 

 adapted for climbing. The limbs and the stout body, with the excep- 

 tion of the middle of the back, are clothed with long fine, almost 

 woolly hair. Intermixed with this along the sides and over the nape 

 is a wide band of stiff, coarse, grey-tipped hair about six inches long, 

 and the forehead bears a short tuft of grey bristles. Along the middle 

 of the back and out to the end of the short tail grows a dense mass of 

 erectile quills, mixed with a few long black hairs. The quills are of 

 all lengths from less than an inch to three and a half or four inches 

 long. In addition to this principal mass, there is a scattered growth 

 of short but stout quills concealed in the hair all along the sides and 

 over the head, extending low down on the forehead and above the 

 eyes. Only the underparts of the animal are entirely free from the 

 spines. 



I have never come across the young of the porcupine myself, but 

 I am informed by Mr. C. W. Nash that they are born in May, two to 

 four in a litter, and are at birth extremely large in proportion to the 

 size of the adults. They are covered with long black hair interspersed 

 with quills about half an inch in length. 



The quills of the adult are white at the base, shading towards 

 the top into yellow and dark brown to black. The largest of them 

 are iy 2 inches to 4 inches long (approximately, 90 mm. to 100 mm.) 

 and about 1/16 inch (approximately 2 mm.) in diameter at the thick- 

 est part. They are clearly only modified hairs, and various types may 

 be found on the same animal, ranging from plain stiff bristles through 

 slender smooth-pointed spines up to stout needle-sharp barbed quills. 

 The quills are loosely held in the soft fat skin by a conical root with a 

 rounded shoulder, and they appear to come out at the slightest touch. 

 Indeed, before trying some experiments I could not understand why 

 they did not all fall out ( in the ordinary stress of daily life; and I 

 formulated a theory, that when the quills were in their normal 

 depressed position, they were held in the skin more firmly than when 

 they were erected to stand off an enemy. Herbert Spencer's friends 

 said that the philosopher's sole idea of a tragedy was a beautiful 

 theory killed by a devilish little fact. In my case the little fact was 

 that the quills were not held more firmly in one position than in 

 another. Admittedly, the porcupine I experimented with was a dead 

 one, but I cannot see that there would be any difference in the result in 

 life. The truth is that it requires a pull of a quarter of a pound or 

 so to free the quills from their sockets, and no ordinary friction to 

 which they are subjected is sufficient to remove them. But when once 

 the point of the quill is caught in the flesh of an enemy, the barbs 

 hold it so firmly that it readily pulls out of the porcupine's skin. 



