Chap. II.] MENTAL POWERS. 49 



ning, and may have lost in wariness and suspicion, yet 

 they have progressed in certain moral qualities, such as in 

 affection, trustworthiness, temper, and probably in gen- 

 eral intelligence. The common rat has conquered and 

 beaten several other species throughout Europe, in parts 

 of North America, New Zealand, and recently in For- 

 mosa, as well as on the main-land of China. Mr. Swin- 

 hoe," who describes these latter cases, attributes the vic- 

 tory of the common rat over the large Mus coninga to 

 its superior cunning ; and this latter quality may be at- 

 tributed to the habitual exercise of all its faculties in 

 avoiding extirpation by man, as well as to nearly all the 

 less cunning or weak-minded rats having been successively 

 destroyed by him. To maintain, independently of any 

 direct evidence, that no animal during the course of ages 

 has progressed in intellect or other mental faculties, is to 

 beg the question of the evolution of species. Hereafter 

 we shall see that, according to Lartet, existing mammals 

 belononn^ to several orders have larger brains than their 

 ancient tertiary prototypes. 



It has often been said that no animal uses any tool ; 

 ' but the chimpanzee in a state of nature cracks a native 

 fruit, somewhat like a walnut, with a stone. 23 Rengger 24 

 easily taught an American monkey thus to break open 

 hard palm-nuts, and afterward of its own accord it used 

 stones to open other kinds of nuts, as well as boxes. It 

 thus also removed the soft rind of fruit that had a disa- 

 greeable flavor. Another monkey was taught to open the 

 lid of a large box with a stick, and aftecward it used the 

 stick as a lever to move heavy bodies ; and I have myself 

 seen a young orang put a stick into a crevice, slip his 



22 'Proc. Zoolog. Soc.' 1864, p. 186. 



23 Savage and 'Wyman in 'Boston Journal of Nat. Hist.' vol. iv. 1843 

 -'44, p. 383. 



24 'Saugethiere von Paraguay,' 1830, s. 51-56. 



