MENTAL POWERS. 77 



of fixed, though not inherited habits; for as a sagacious 

 physician remarked to me, persons who are slightly imbecile 

 tend to act in ftvftrythiii g by routine or hab it; and they are 

 rendered much happier if this is encouraged. 



I have thought this digression worth giving, because we 

 may easily underrate the mental powers of the higher ani- 

 mals, and especially of man, when we compare their actions 

 founded on the memory of past events, on foresight, reason 

 and imagination, with exactly similar actions instinctively 

 performed by the lower animals; in this latter case the 

 capacity of performing such actions has been gained, step 

 by step, through the variability of the mental organs and 

 natural selection, without any conscious intelligence on the 

 part of the animal during each successive generation. No 

 doubt, as Mr. AVallace has argued,* much of the intelligent 

 work done by man is due to imitation and not to reason; 

 but there is this great difference between his actions and 

 many of those performed by the lower animals, namely, 

 that man cannot, on his first trial, make, for instance, a 

 stone hatchet or a canoe, through his power of imitation. 

 He has to learn his work by practice; a beaver, on the other 

 hand, can make its dam or canal, and a bird its nest, as 

 well, or nearly as well, and a spider its wonderful web, 

 quite as well,f the first time it tries as when old and 

 experienced. 



To return to our immediate subject: the lower animals, 

 like man, manifestly feel pleasure and pain, happiness and 

 misery. Happiness is never better exhibited than by 

 young animals, such as puppies, kittens, lambs, etc. , when 

 plaWng together, like our own children. Even insects 

 play together, as has been described by that excellent 

 observer, P. Huber,| who saw ants chasing and pretending 

 to bite each other, like so many puppies. 



The fact that the lower animals are excited by the same 

 emotions as ourselves is so well established that it will 

 not be necessary to weary the reader by many details. 

 Terror acts in the same manner on them as on us, causing 

 the muscles to tremble, the heart to palpitate, the 



* " Contributions to the Theory of Natural Selection," 1870, p. 212. 



f For the evidence on this head, see Mr. J. Traheme Moggridge's 

 most interesting work, " Harvesting Ants and Trap-door Spiders, ' 

 1873, pp. 126, 128. 



X " Recherches sur les Moeurs des Fourmis," 1810, p. 173. 



