19G 



KNOWLEDGE 



[Jan. C, 1882 



into tlifir digestive systems hy means of n tiil)e or duct. 

 Hut ill many tislies fliis tulic disappears, Ir-aving the air- 

 bladder a dosed saf (as in the tod) ; or tlie iluct may 

 persist, and place the sound in communication witli the 

 digestive tract, as in the sturgeon or herring. Again, the 

 air-liladder may lie a simplf and single sac ; or it may lie 

 variously divided, and its interior may ho smooth or may 

 he divided into cells. We shall presently .see that in the 

 mudfi.shes and the " Jeevine," this structure assumes a 

 form and function for which its variations in common fishes 

 in some measure prepare us. 



I^'TELLIGENCE IN ANIMALS. 



IT may he olijected that in cases such as those we con- 

 sidered la-st, the animal has merely imitated an action 

 which it ha.s seen performed liy others, and has subsequently 

 learned to associate the action with its ordinary consequence. 

 Apart from the consideration, however, that although in 

 any single case such an interpretation might possibly bo 

 correct, it would be most improbable that it should explain 

 all cases in which cats or dogs have .used knockers or rung 

 bells in the usual «ay, cases may be cited in which animals 

 have devised a way of their own for producing such 

 signals. Thus Mr. E. L. Layard, of the British Consulate, 

 Noumea, relates the following case in which a cat acted 

 in a way which can hardly be explained, save by assu- 

 mrng that she reasoned : — " Many years ago," he says, " we 

 lived in Cambridge, in Emmanuel House, at the back of 

 Emmanuel College. The premises were partly cut off from 

 the road by a high wall ; the body of the house stood back 

 some little di.stance. A high trellis, dividing off the garden, 

 ran from the entrance door to the wall, in which was 

 another door, or grate. A portion of the house, a gable, 

 faced the trelli.s Wo were, after some time of resi- 

 dence, extremely troubled by runaway rings, generalh' 

 most prevalent at night, and in rainy, bad, or cold weather, 

 which was a great annoyance to the servant girls, who had 

 to cross the space between the house and the wall to open 

 the outer door in the latter, and were thus exposed to wet 

 and cold." The annoyance became so great, that Mr. 

 Layard and a cousin watched behind the trees on 'Jesus' 

 piece,' armed with stout ash saplings, wherewith to ad- 

 minister a sound thrashing to the ringer, whomsoever he 

 might be. iJut though the rings continued, no one pulled 

 the handle. Hence the theory of ghosts was naturally 

 suggested, but Mr. Layard, having brains, rejected 

 that interpretation. At length chance cleared up the 

 mystery. -'Being ill," he sa3\s, "I was confined to 

 the wing facing the trellis, and one miserable, blowing, 

 wet day, gazing disconsolately out of the window, espied my 

 favourite cat — a singularly intelligent animal, much petted 

 — coming along the path, wet, draggle-tailed, and miserable. 

 Pussy marched up to the house-door, sniffed at it, puslicd 

 it, mewed, but, finding it fairly shut, clambered up to the 

 top of the trellis, .some eight or ten feet from the ground, 

 reached a paw over the edge, scratched till she found the 

 bell-wire which ran along the upper rail from the wall to 

 the house, caught hold of it, gave it a hearty pull, then 

 jumped down, and waited demurely at the door. Out came 

 the maid ; in ruslie(l puss. The former, after gazing 

 vaguely up and down the street, returned, muttering 

 ' blessings,' nf) doubt, on the ghost, to be confronted by me 

 ill the hall. ' Well, Lydi.i, I have at last found out who 

 rings the bell.' 'Lard, master, ye haven't, surely' — she 

 was broad Zumer/etsheer. ' [ have ; come and see. Look 

 out of the, bri-akfast-i-oom window, l)ut don't .show your- 

 - '■■' Meanwhile I vent into the drawing-room, where 



.sell.' 



Mrs. Puss was busy drying herself before the fire. Catching 

 her up, I popped her outside of the door and ran round to 

 my post of observation. Pu.ss tried the door, and mewed, 

 thinking, probably, .someone must be near, and, after waiting 

 two or three minutes in vain, again sprang up the trellis 

 and renewed her attack on the bell-wire, of course, to \>e 

 immediately admitted by the delighted maid, who this 

 time did 710/ cross the yard, nor ever again, I fear some- 

 times to the inconvenience of \isitors, if puss was waiting 

 for admi.ssion." 



In this case it is possible that the cat may have only dis- 

 covered by accident that the bell-wire could be reached in 

 the way described. Tliis is Mr. Laj-ard's explanation. He 

 considers that puss, in clambering up the trellLs to the house- 

 top, accidentally moved the wire and caused the bell to 

 ring. It seems at least as likely that she noticed the wire 

 moving when the bell was rung, and afterwards deliberately 

 moved it to produce the desired effect. But in either case, 

 it is clear that neither instinct nor mere imitative faculty 

 can explain the cat's action in this case. In passing, I may 

 remark that the imitative faculty, which some regard as a 

 merely automatic quality, seems to me far better explained 

 as the result of reasoning, though, of course, the reasoning 

 is not of a very high order ; an animal seeing a man per- 

 form some action, infers that some advantage is to be 

 gained by the action, and repeats it in the expectation 

 that some good result will follow, though without knowing 

 what this may Vie. However, in the present case, there 

 was no imitation, nor certainly could any instinct have 

 been in question. Mr. Layard mentions other cases, of 

 which the same may be said. " I have known dogs shake 

 a door violently," he says, " to attract attention and be let 

 in. A dear old spaniel of ours at the Cape used to rattle 

 the empty bucket if he was thirsty, and then come and 

 look in our faces. My horse will come up from his pasture 

 to the pump in the yard, and whinny till someone giv< 



him water Surely all this is abstract reasoning." he 



proceeds. " Tliese things are not taught them, and they do 

 not do all of them even by imitation. I don't go to the 

 pump and whinny if I want drink ! nor rattle a bucket ! 

 No ! they come by a process of mental reasoning, and I am 

 convinced all animals have it to a certain degree, more or 

 less." 



There have been cases which have afforded opportunity 

 of noting the behaviour of an animal when first some new 

 experience has occurred to it, and (as it would seem) new 

 ideas have been suggested. Such cases are of extreme 

 importance in determining whether animals really reason 

 or not ; because it must be admitted that in some instances 

 where animals have appeared to reason, the action noted 

 may possibly have originated, in the first instance, by acci" 

 dent, and have been continued subsequently as a men 

 h;ibit. It is rather unfortunate that the only animal/ 

 which we can observe under favourable conditions — do 

 mestic animals, and those which, though not domestic 

 affect the neighbourhood of houses — are not those whos« 

 cerebral development is of the highest order among animalsi 

 If monkeys were commonly domesticated (which would 

 for other reasons, be by no means desirable), we should pr 

 bably have a number of far more striking and convincing 

 in.stances of animal reasoning than we at present po.ssess, 

 for nearly all monkeys are far higher in cerebral develop- 

 ment than the most sagacious dogs, while horses, cats, rats, 

 A'c, are lower than dogs in this respect Still, if wo. 

 remember that whatever e\-idence we obtain from the; 

 behaviour of dogs and cats must be regarded as suggest- 

 ing, for this very reason, a powerful argument a fortiori 

 as to th<> reasoning faculties of monkeys, and especially of 

 the higher orders of simians, we may be well satisfied with 



