496 



NATURE 



\J\Iarck 27, 1879 



INTELLECT IN BRUTES 



\^E have received so many letters on this subject that we are 

 * ' compelled to content ourselves with giving the following 

 extracts ; — 



The Rev. George Henslow comments as follows on some of 

 the cases already adduced : — 



I would not assert that what I call "practical reasoning" — 

 that is, reasoning applied to objective facts directly apprehended 

 by the senses — is fimdamentally different from "abstract," i.e., 

 with no objective fact immediately present to consciousness ; 

 but they certainly do represent two stages in our own mental 

 development. 



E. H. Pringle's account of "Bully" shows nothing beyond 

 what is canmion to dogs in practical cunning {i.e. reasoning) with 

 objective things, (i) his "lady" friend, (2) best road to take so as 

 not to be seen, (3) the person to be avoided, (4) E. H. Pringle's 

 eye to be eluded. In the only point where abstract reflection 

 was really required Bully failed, just as a child would, viz., in 

 shamming sleep. For, it is not enough to lie dcnvn and shut onis 

 eyes. This is all a child is told to do, or is conscious of doing 

 on going to sleep. The relaxation of eveiy muscle follows 

 spontaneously. Hence, as children do not think of this when 

 pretending (since it requires reflection) they can so easily be 

 detected by some rigidity of the muscles in the face or in 

 breathing which at once betrays them. I have known a child 

 overdo it by screwing up its eyes in order to appear very fast 

 asleep ! Exactly so, too, Bully was totally unable to think of the 

 importance of putting his ears in repose. 



Dr. Rae's dog only strengthens my case, for it clearly asso- 

 ciated the bell with a particular maid, whereas a reasoning 

 human being would have generalised that since the maid was in 

 the room, the bell could be rung for some one else. Hence the 

 dog proved its impotency in all power of generalisation, which is 

 a pure form of abstract reasoning. 



Dr. Muirhead's donkey was solely concerned with immediate 

 sense-objects, the gate and the cows, and required no abstract 

 reflection. That horses and donkeys can discover how to open 

 gates is by no means uncommon. 



Lastly C.M.'s cat and Mr. Belsham's kitten are the only cases 

 I have yet seen which show a primd facie evidence against the 

 distinction I propose to draw. But, that a half-grown kitten 

 could go through such a process of reflection analogous to what 

 I gave for a hypothetical untaught dog ringing a bell, would 

 be so astounding, that all possible explanations must be 

 eliminated first, before it is credited. 



Is it not far more probable that the cat and the kitten dis- 

 covered by accident that the door was opened when a knock was 

 made, and that this discovery arose from the common habit of 

 cats to play with anything suspended within their reach? That 

 animals discover facts, and then use them, will not be disputed, 

 like the dog that, on discovering a stream carried him down too 

 far on swimming across it, ran a mile up stream ever afterwards 

 to allow for the current. Again, that animals mimic, as do 

 parrots and apes, is commion enough, but they do not know why 

 they do it. A monkey might knock at a door after seeing a 

 man do it, but, I believe, could have no similar motive as the 

 man, until (like the kitten) it should accidentally discover for 

 itself what the real use was, or else unless it be taught to do it. 



In re rats gnawing pipes. I have just heard of a mouse 

 gnawing through a gas-pipe. May it not be accounted for by 

 the fact that, although the upper incisors of a rodent, by work- 

 ing on the lower, keep the chisel-like ends in order ; yet this 

 may be assisted by gnawing wood, lead, or other hard sub- 

 stances ? Does not this account for rabbits, though well fed on 

 cabbage and bran, &c., still persisting in gnawing their hutches ? 

 I will, in conclusion, give another case to illustrate the want 

 of abstract reflection : this time in a lady (aged thirty), whose 

 mental powers were curiously arrested. Looking at the picture 

 of a shark in the sea, with a pig in its mouth, in " Masterman 

 Ready," and knowing that the pig had been dropped from the 

 wreck to see if it would swim to shore, she 7iaively asked, "Is 

 the shark carrying the pig to the shore ? " The idea of the shark 

 eating the pig would 'only arise from the abstract reflection on 

 the habits of sharks, which was not suggested by the story ; the 

 single objective fact present to her mind was that " the pig had 

 to get to the shore." 



Mr. Arthur Nicols writes : — 



I cannot understand practical reasoning, but a practical result 

 of reasoning upon either simple or abstract ideas is intelligible. 



Can we conceive any human being reasoning more correctly than 

 a dog did in the following instance? — Towards the evening of a 

 long day's snipe-shooting on Dartmoor, the party was walking 

 down the bank of the Dart, when my retriever flushed a widgeon 

 which fell to my gun in the river, and of course instantly dived. 

 I said no word to the dog. He did not plunge in after the 

 widgeon there, but galloped do'iun stream about fifty or sixty 

 yards, and then entered the water, and dashed from side to side 

 — it was about twenty or thirty feet wide — working up stream, 

 and making a great commotion in the water, until he came to 

 the place where we stood. Then he landed and shook himself, 

 and carefully hunted the near bank a considerable distance 

 down, crossed to the opposite side, and diligently explored 

 that bank. Two or three minutes had elapsed, and the 

 party was for moving on, when I called their attention 

 to a sudden change in the dog's demeanour. His "flag" 

 was now up, and going from side to side in that energetic 

 manner which, as every sportsman knows, betokens a hot 

 scent. I then knew that the bird was as safe as if it was already 

 in my bag. Away through the heather went the waving tail, 

 until, twenty or thirty yards from the bank opposite to that on 

 which we \\ere standing, there was a momentary scuffle ; the 

 bird just rose from the ground above the heather, the dog sprang 

 into the air, caught it, came away at full gallop, dashed across 

 the stream, and delivered it into my hand. Need I interpret all 

 this for the experienced sportsman ? The dog had learned from 

 long experience in Australia and the narrow canadas in the La 

 Plata that a wounded duck goes down stream— if winged, 

 his maimed wing sticks out, and renders it impossible for 

 him to go up — and will invariably land, and try to hide away 

 from the bank. But if the dog enters at the place where 

 the bird fell, the latter will go on with the stream for 

 an indefinite distance, rising now and then for breath, and 

 give infinite trouble. My dog had found out all this long 

 since, and had proved the correctness of his knowledge 

 times out of number, and by his actions had taught me the 

 whole art and mystery of retrieving duck. His object — I say, 

 without a doubt, because I had had numberless opportunities 

 of observing it — was to flurry the bird and force it to land by 

 cutting it off lower down the stream. Then assuming, as his 

 experience justified him, that the bird had landed, he hunted 

 each bank in succession for the trail, which he knew must 

 betray the fugitive. 



Mr. A. Petrie writes : — In my own family we had a tabby 

 cat, who, when turned out, would let herself in at another door 

 by climbing up some list nailed round it, then pushing up 

 the click-latch, pushing the door, with herself hanging on it, 

 away from the post, so as to prevent the latch falling back into 

 its place, and then dropping down and walking back to the fire. 

 I knew a Skye terrier, who, being told to carry a fishing- 

 rod, carefully experimented along its length, to find its centre of 

 gravity, then carried it on till his master came to a narrow path 

 through a wood. Here Skye considered, dropped the rod, took 

 it by the end, and dragged it under him lengthwise, till the open 

 road was gained, when he took the rod by the centre of gravity 

 again, and went on. This could not be a coj)y of human actions, 

 but the result of original reasoning. 



Mr. Henry Cecil gives the following on the authority of the 

 late Mr. Dawes the astronomer : — 



Being busy in his garden, and having a large bunch of keys in 

 his hand, he gave it to a retriever to hold for him till he was at 

 liberty. Going into the house soon after he forgot to reclaim 

 the keys. The remembrance of what he had done with them 

 only returned to him when he required to use them in the 

 evening. He then recalled that he had given them to the dog, 

 and forgotten to take them again. Calling him, and looking 

 impressively in his face, he said, "My keys! fetch me my 

 keys." The dog looked wistful and puzzled for a moment, and 

 then bounded off to the garden, his master following. He 

 went straight to the root of an apple-tree, scratched up the keys, 

 and brought them. May we not fairly put into words the dog's 

 train of reasoning thus : " My master has given me these keys to 

 hold ; he has forgotten them ; I cannot carry them all day ; but 

 I must put them in safety where I can find them again ? " 



Mr. W. S. Chamberlayne writes that many years ago, taking 

 an afternoon ride through a wood in the Bahamas, he came to a 

 gate which was kept closed by a small iron hoop hung over a 

 post and the end of the gate. To open the gate he leant over 

 his horse's neck and lifted up the hoop, shutting the gate 



