48 THE DESCENT OF MAN. [Part I. 



alone is capable of progressive improvement. With ani- 

 mals, looking first to the individual, every one who has 

 had any experience in setting traps knows that young 

 animals can be caught much more easily than old ones ; 

 and they can be much more easily approached by an 

 enemy. Even with respect to old animals, it is impossible 

 to catch many in the same place and in the same kind of 

 trap, or to destroy them by the same kind of poison ; yet 

 it is improbable that all should have partaken of the poi- 

 son, and impossible that all should have been caught in 

 the trap. They must learn caution by seeing their breth- 

 ren caught or poisoned. In North America, where the 

 fur-bearing animals have long been pursued, they exhibit, 

 according to the unanimous testimony of all observers, an 

 almost incredible amount of sagacity, caution, and cun- 

 ning ; but trapping has been there so long carried on that 

 inheritance may have come into play. 



If we look to successive generations, or to the race, 

 there is no doubt that birds and other animals gradually 

 both acquire and lose caution in relation to man or other 

 enemies ; 19 and this caution is certainly in chief part an 

 inherited habit or instinct, but in part the result of indi- 

 vidual experience. A good observer, Leroy, 20 states that 

 in districts where foxes are much hunted, the young when 

 they first leave their burrows are incontestably much 

 more wary than the old ones in districts where they are 

 not much disturbed. 



Our domestic dogs are descended from wolves and 

 jackals, 21 and though they may not have gained in cun- 



M ' Journal of Researches during the Voyage of the " Beagle," ' 1845, 

 o. 398. ' Origin of Species,' 5th edit. p. 260. 



20 ' Lettres Phil, sur Tlntelligence des Animaux,' nouvelle edit. 1802, 

 p. 86. 



21 See the evidence on this head in chap. i. vol. i. ' On the Variation 

 ol Animals and Plants under Domestication.' 



