CANADA PORCUPINE 7 



duction, usually one each 3^ear after the second 3^ear, one would 

 judge it to be a long series of years. Shiras' (36) flashlight 

 records of an albino for six consecutive summers is the only 

 account of prolonged study that has been published. Porcu- 

 pines do not thrive well in the cage and have never been known 

 to breed in captivity. The former circumstance is difficult to 

 explain. Each of the animals in this study which died has 

 apparently succumbed to a different malady so that no general- 

 izations have been possible. Dr. Hornada}^ writing of the 

 Canada porcupine in the guide to New York Zoological Garden, 

 May ist, 1907, says: "It is only the men who know all about 

 animals who can tell us why nothing seems to satisfy them, and 

 why they will not breed here, live 10 years and be happy." 

 But even these men have not found the remedy. 



Concerning the fact that they will not breed in captivity 

 only one explanation is suggested. If the report of hunters 

 and woodsmen who have witnessed the act can be credited, 

 copulation is a very complex process, — so complex indeed, as to 

 involve submission on the part of the female more complete 

 than is ordinarily found among higher vertebrates. During 

 sexual congress, the female is said to lie on her back with the 

 male directly above her, — a submission hardly probable under 

 the strained and limited conditions of cage life. The w^riter 

 does not vouch for these facts, although there are identical 

 reports of eye-witnesses on various occasions and there seems 

 to be no other physiological possibility than for the bodily 

 contact during the sexual embrace to be on parts of the body 

 where there are no quills. The position and structure of the 

 sex organs are entirely consistent with this report from the 

 woodsmen. There seems to be no means by which the male 

 could capture or hold the female during copulation. 



The young of the porcupine have never been studied and 

 have probably never been seen alive. Observations in this 

 study are limited to three infant porcupines, two of which were 

 taken dead from the body of the mothers which had died before 

 undergoing labour, and a third taken dead from the mother 

 after a failure at labour, the mother dying a few days later. 

 One of these young may be described as follows: Length of 

 body was six inches, and of tail two inches. Whole outer sur- 

 face was covered with rather coarse hair, with no quills, but 



