328 MENTAL EVOLUTION OF ANIMALS. 



— there we must suppose that inference of the second stage 

 obtains. And, although we are not able to draw the lines 

 with precision, we know that both these conditions occur low 

 down among the Invertebrata. 



The next stage of inference is the highest that obtains 

 among animals. This is the stage in which objects, qualities, 

 and relations are deliberately compared with the intention of 

 perceiving likenesses and unlikenesses (analogies); the action 

 which follows is therefore undertaken with a knowledge, or 

 perception, of the relation between the means employed and 

 the ends attained. This, as I have before said, is the stage of 

 the process of inference at which the term Eeason or Ratio- 

 cination first becomes appropriate, and therefore it is with 

 reference to this stage that I first use the word. That this 

 stage of the process of inference is reached by nearly all the 

 warm-blooded animals, and even by some of the Invertebrata, 

 no one, I think, can possibly question. If, however, any one 

 should do so, I must refer him to my previous work ; for the 

 instances there given are so numerous that it would be tedious 

 here to reproduce even the more striking among them.* To 

 my mind the most remarkable of these instances are those 

 which have reference to the Hymenoptera ; for although the 

 faculty does not attain to so high a level of development 

 among them as it does among some of the warm-blooded 

 Vertebrata, it certainly has attained to much more than a 



* For the sake at once of giving a striking example of reason in an 

 animal most nearly approaching man, and of supplementing a deficiency in 

 my former treatise, I shall here quote a passage from Dr. Bastian's work on 

 The Brain as an Organ of Mind (p. 329). " In regard to the high degree of 

 Intelligence of the Orang, we have the following, on the best of testimony, 

 from Leuret, who says (Anat. Comp. du Si/st. A"erv., torn, i, p. 540) : — 



" ' One of the Orangs, which recently died at the Menagerie of the Musce, 

 ■was accustomed, when the dinner-hour had come, to open the door of the 

 room where he took his meals in company with several persons. As he was 

 not sufficeintly tall to reach as far as the key of the door, he hung on to a 

 rope, balanced himself, and after a few oscillations very quickly reached the 

 key. His keeper, who was rather worried by so much exactitude, one day 

 took occasion to make three knots in the rope, which, having thus been made 

 too short, no longer permitted the Orang-outang to seize the key. The 

 animal, after an ineffectual attempt, recognizing the nature of the obstacle 

 which opposed his desire, climbed tip the rope, placed himself above the knots, 

 and untied all three, in the presence of M. Gcoffroy Saint-Hilaire, who related 

 the fact to me. The same ape wishing to open a door, his keeper gave him a 

 bunch of fifteen keys ; the ape tried them in turn till he had found the one 

 which he wanted. Another time a bar of iron was put into his hands, and he 

 made use of it as a lever." ' 



