/IMERICAN PORCUPINES 



Family Erethisontid<2 



Wherever found porcupines may always be known by their 

 spines. The short legs, plantigrade feet and short thick tail are also 

 characteristic of our North American species, but foreign porcupines 

 exhibit many differences in their structure, one kind found in South 

 America having a long prehensile tail like our opossum. The quills 

 or spines of the porcupine are scattered about amongst the hair and 

 all point backward but may be elevated at will by the muscular con- 

 traction of the skin and being so loosely attached at the base are 

 frequently impaled in the face or feet of any animal which may come 

 in contact with them. 



In the Canada porcupine the quills are usually shorter than the 

 hair but in certain foreign species they are greatly developed. 



Besides the Canada porcupine we have one other closely allied 

 species in North America, the yellow-haired porcupine {Erethi\on 

 epixanthus) of British Columbia and western United States. 



Canada Porcupine 



Ercthizon dorsatus (Linnaeus) 



Length. 28 inches. 



Description. Dark-brown to nearly black, quills tipped with yellow- 

 ish, two to four inches long mostly concealed by the hair, which 

 reaches a length of six inches; toes, four on the front feet and five 

 on the hind. 



Range. Northern parts of North America south to Maine and in 

 the higher mountains of Pennsylvania. Not found south of the 

 Canadian faunal zone. 



The porcupine is much more interesting as a species than as an 

 individual. Looked at either as an example of the beneficent protection 

 which is rendered to every creature according to its needs, or as a 

 branch of the rodent family that has succeeded in perfecting a most 

 unique method of defence through the law of the survival of the 

 fittest, it furnishes an interesting study. 



94 



