38 SPINY ANIMALS. 



mammals to acquire some special means of protection in 

 order to be able to hold their own among the higher 

 forms. As our readers are doubtless aware, in mammals 

 spines are nothing more than specially modified hairs, and 

 in a porcupine the transition from a spine to an ordinary 

 hair can be easily seen. There are many rodents in which 

 a certain number of scattered spines are mingled with the 

 fur of the back, but our remarks will be confined in the 

 main to the forms in which the spines predominate suffi- 

 ciently to render them the most striking feature in the 

 external appearance of their possessors. 



Commencing with the rodents, our first representatives 

 of the spiny mammals will be the true porcupines (Hystrix), 

 which are such well-known creatures as to require but 

 brief description. These animals conform, of course, to 

 the ordinary rodent type in having a single pair of large 

 chisel-like incisors in each jaw ; and their spines are most 

 developed on the middle line of the head and back, 

 the hinder part of the body, and 011 the short tail. 

 Whereas, however, those on the body are solid throughout 

 and pointed at each end, the spines at the extremity of 

 the short tail are in the form of hollow quills inserted by 

 narrow stalks. It is these hollow quills that make the 

 loud rattling sound heard when a porcupine is walking ; 

 and it appears to us not improbable that they may have 

 given rise to the old legend of the porcupine ejecting its 

 spines when attacked, as such hollow quills might well 

 have been thought to be receptacles for the ordinary 

 spines. Although their owner is unable to voluntarily eject 

 the latter, their pointed bases render them easily detached, 

 and leopards which habitually feed on porcupines are 

 found to be actually bristling with their quills. In attack- 

 ing its foes, the porcupine rushes at them backwards, and 

 thus gives full effect to its weapons. All the members of 

 the typical genus are characterized by their large size, 

 short tails, and highly convex skulls, and are confined to 

 the warmer regions of the Old World. The brush-tailed 

 porcupines (Atherura) from West and Central Africa and 

 the Malayan region are, however, of much smaller size, 

 and also distinguished by their much longer tails, which 



