80 The Descent of Man. Part I. 



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 poison, and impossible that all should have 

 been caught in a trap. They must learn caution by seeing their 

 brethren 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 cunning ; but trapping has been 

 there so long carried on, that inheritance may possibly have come 

 into play. I have received several accounts that when telegraphs 

 are first set up in any district, many birds kill themselves by 

 flying against the wires, but that in the course of a very few 

 years they learn to avoid this danger, by seeing, as it would 

 appear, their comrades killed. 32 



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 ; 33 and this 

 caution is certainly in chief part an inherited habit or instinct, 

 but in part the result of individual experience. A good observer, 

 Leroy, 34 states, that in districts where foxes are much hunted, 

 the young, on first leaving 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, 35 

 and though they may not have gained in cunning, and may have 

 lost in wariness and suspicion, yet they have progressed in 

 certain moral qualities, such as in affection, trust-worthiness, 

 temper, and probably in general intelligence. The common rat 

 has conquered and beaten several other species throughout 

 Europe, in parts of North America, New Zealand, and recently in 

 "Formosa, as well as on the mainland of China. Mr. Swinhoe, 36 

 who describes these two latter cases, attributes the victory of the 

 common rat over the large Mus coninga to its superior cunning ; 

 and this latter quality may probably be attributed to the habitual 



82 For additional evidence, with 34 ' Lettres Phil, sur l'lntelligence 



details, see M. Houzeau, ' Les des Animaux,' nouvelle edit. 1802, 



Facultes Mentales,' torn. ii. 1872, p. 86. 



p. 147. 3j See the evidence on this head 



33 See, with respect to birds on in chap. i. vol. i. ' On the Variation 

 oceanic islands, my ' Journal of of Animals and Plants under Do- 

 Researches during the voyage of the mestication.' 



" Beagle," ' 1845. p. 308. ' Oriein 36 < Proc. Zoolog. Soc.' 1864, p 



of Species,' 5th edit. p. 260. 1P6. 



