CHAPTER VIII. 



FECUNDITY. 



THE conditions of the animal organization that 

 have an influence upon the function of reproduction 

 seem to require more than a passing notice. The fer- 

 tility of animals is frequently influenced by changes 

 in their surroundings and habits that cannot, in them- 

 selves, be considered unfavorable to the healthy action 

 of the system. 



It has been observed that the procreative powers 

 .are impaired, or even entirely wanting, in many wild 

 species, when placed in confinement. The elephant, 

 the tiger, squirrels, monkeys, parrots, and many other 

 animals, it is said, rarely, if ever, breed when subject- 

 ed to man's control. Mr. Darwin, on the authority of 

 Mr. Bartlett, records the remarkable fact that " lions 

 breed more freely in traveling collections than in the 

 Zoological Gardens." 1 



The flying-squirrel, when breeding in captivity, 

 has not been known to produce more than two young 

 at a birth, while in a state of nature it produces from 

 three to six." 



"The African ostrich, though perfectly healthy 



1 "Animals and Plants under Domestication," vol. ii., p. 185. 

 8 Darwin, loc. cit., p. 187. 



