April I, 1879] 



NATURE 



519 



Belcher ; five European Geckos (Phyllodactylus citropans) from 

 Italy, presented by Prof. H. H. Giglioli, C.M.Z.S. ; a Cape 

 Ant-bear {Orycheropus capensis) from South Africa, purchased. 



INTELLECT IN BRUTES 



"IXTE have another batch of letters on this subject, the essential 

 points of which we shall endeavour to give in brief space : — 



Mr. Wm. Hogg tells us of an incident he witnessed when 

 calling on Mr. W. H. Michael, a gentleman well known at the 

 parliamentary bar, who resides at Queen Anne's Gate, St. James's 

 Park. While they were sitting in the study, the French 

 window of which communicates with a garden at the back of 

 the house, and had a crank latch by which it could be opened 

 on either side, a cat presented herself outside the window, 

 pleading for admission. She continued to plead for some time, 

 and finding no help from within she resolved to trust to her own 

 powers. Eying the latch, which was four feet above her, she 

 made a spring, caught hold of the crank with her fore feet, and 

 putting her hind feet against the other half of the window as a 

 fulcrum she pressed open the vs-indow. This she would do 

 several times in succession. Mr. Michael informed Mr. Hogg 

 that the cat had never been taught to do this. 



D, R. S . sends the story of a little terrier that left her puppies 

 only once a day to be fed, gulping down hurriedly a great quantity 

 of porridge. Retiuming quickly to her family she would put up 

 all the porridge in order that she and her puppies might together 

 enjoy a hearty meal. When the terrier was scolded for a fault 

 it rushed away to a little distance and catching up anything it 

 could get hold of at once — a bit of stick, a straw, a slipper or 

 anything at hand — it would come coweringly and lay it down at 

 our feet, with an expression of utter submission. If we were 

 not propitiated it would run off a second time and bring another 

 peace-offering, often in its distress catching things it would not 

 at any other time have dared to touch. 



M. W. T. writes : — A farmer, in Somersetshire, was going to a 

 neighbouring village some three miles distant, and, not wishing 

 to take his dog he ordered him home. The dog reluctantly 

 obeyed. When the man arrived at a spot, about half way on 

 his road, where the short cut he had taken across the fields 

 joined the more circuitous road, he found the dog waiting for 

 him. Evidently the animal had taken the longer route, which 

 he doubtless knew, calculating on meeting his master at that 

 point, and thus gaining his end without hindrance. 



Mr. John Harmer, of Wick, Artmdel, possessed a few 

 years ago a very fine and intelligent tom-cat which was much 

 addicted to plundering a rabbit-warren about a mile from his 

 home. Alter a time it was noticed that before he proceeded on 

 one of his expeditions " Sam " completed his toilet by wallowing 

 in the filth turned out of the tame rabbits' hutches, he taking 

 particular care that his neck and breast should be in as disgusting 

 a condition as possible by smearing them up and down till both 

 were saturated and the fur all matted together. 



Mr. J. J. Cole of Mayland, Sutton, Surrey, writes : — It 

 has been my custom to have— not a letter-box in a door in the 

 usual way but the plate and flap in the bottom of a window 

 sash near. I had a cat which often saw a servant go to the 

 window on hearing the flap moved by the postman, and which, 

 when shut out used to jump on to the window sill and rattle the 

 flap and when the servant was seen through the glass jump down 

 to be let in at the door. I knew a horse which during week days 

 went round and round to the left, grinding in the cellar of a snuff 

 maker in London. On Sundays his owner turned him out in 

 a field at his place in the country where the horse went round 

 and round all day long unwinding himself the other wav 

 W^hy? '■ 



Mr. B. G. Jenkins describes a scene he witnessed between the 

 large insect known as " daddy long-legs " and a small spider. 

 The former got caught by one of its hind-legs by a pendant 

 thread of cobweb about eight inches long, at the other end of 

 which was the small spider. The spider cautiously descended 

 on the thread, doubling it as he came, and secured the insect's 

 leg more firmly. He then ascended about three inches, and 

 drew the insect up about half an inch ; but a violent resistance 

 on the part of the latter induced him to give up the attempt. 

 He, however, went up the thread, strengthening it as he went, 

 and coming down again to the same place, evidently attempted 



once more to raise his prey, but without success, for the insect 

 resisted so stoutly that it appeared to me to stretch the thread. 

 The spider, Mr. Jenkins writes, saw clearly that the iasect was 

 too strong for him, that he would never be able to draw him up 

 to the centre of his web, and that if he did not take very sum- 

 roary measures he would lose him altogether; so, on the prin- 

 ciple that half a loaf is better than no bread, he set to work to 

 secure a portion of it. The hind-leg of the insect, to which he 

 had his web fastened, was composed of four jointed portions. 

 Round three of these he busied himself weaving a web. Mr. 

 Jenkins noticed particularly that he did not go up to the last 

 jointed portion, that attached to the body. Having well secured 

 these three, he moved up to the joint, and for a few moments 

 appeared perfectly still. Suddenly the insect darted away, 

 leaving three-quarters of its leg behind. What other explana- 

 tion is there than that the spider disconnected it at the joint ? 

 Quietly ascending the thread, which he carried with him, and 

 of course the leg as well, he properly placed the latter, settled 

 down at the union of the two uppermost portions, gorged 

 himself with juices from above and below, and then retired for 

 the night. 



Several correspondents express surprise at Mr. Henslow's 

 position with regard to " abstract " and " practical " reasoning. 

 They think that several of the instances adduced render that 

 position untenable, and prove that in their degree the animals 

 referred to showed themselves possessed of powers of " abstract " 

 reasoning. With regard to the dog and bell story. Dr. Kae 

 writes : — It was never intended to be imderstood that the dog 

 associated the bell with " a. particular xnaXd," as Mr. Henslow 

 puts it ; any of the other servants would have done equally welL 

 The dog could only show his reasoning powers by declining to 

 ring the bell ; for had he rung it, Mr. Henslow or any one else 

 would naturally have said that the "brute" had shown no 

 reasoning powers at all. Mr. Henslow has passed over without 

 notice the fox and gun story, which, by his own definition, 

 was as clearly a case of abstract reasoning as could be adduced, 

 differing only in form of carrying into effect firom what he would 

 have recommended, which, if adopted by jthe fox, would have 

 led to its destruction. 



Dr. G. Frost sends the following good story : — 

 In answer to Mr. Henslow's request for an example of 

 "abstract reasoning" in the lower animals (Nature, vol. xix. 

 p. 433), I beg to subjoin the following : — Our servants have 

 been accustomed during the late frost to throw the crumbs re- 

 maining fi-om the breakfast table to the birds, and I have several 

 times noticed that our cat used to wait there in ambush in the 

 expectation of obtaining a hearty meal from one or two of the 

 assembled birds. Now, so far, this circumstance in itself is not an 

 "example ofabstract reasoning." But to continue: For the la-tfew 

 days this practice of feeding the birds has been left off. The cat, 

 however, with an almost incredible amount of forethought, was 

 observed by myself, together with two other members of the 

 household, to scatter cnmiibs on the grass, with the obvious inten- 

 tion of enticing the birds. I think Mr. Henslow mij^ht now be 

 convinced that animals also possess in an inferior degree that 

 boasted reasoning power which is generally supposed to belong 

 to man alone. 



THE PLANE OF POLARISATION ELECTRO- 

 MAGNETICALLY ROTATED IN A VAPOUR 



T T is known that Faraday did not succeed in proving electro- 

 -'■ magnetic rotation of the plane of polarisation of light in 

 gases, nor have others succeeded. Considering the interest 

 attaching to this question, Herr Kundt and Herr Rontgen lately 

 thought to repeat the attempt with very strong currents and 

 under the most favourable conditions. The result is that they 

 have been able to prove the rotation, at least in the case of sul- 

 phide of carbon vapour. (Their researches have been communi- 

 cated to the Munich Academy.) 



Sulphide of carbon was chosen because, on the one hand, it 

 shows a strong electro-magnetic rotation in the liquid state, and 

 on the other, its vapour has a considerable tension, even at low 

 temperatures. An iron tube was used for inclosure and heating 

 of the substance ; it was closed at the two ends with glass plates 

 I ctm. thick, and itself inclosed in a tin-plate tube ; so that 

 steam could be led between the tubes to heat the inner tube 

 throughout to 100°. The outer tube was surrounded by six large 

 wire-coils, each having 400 windings of wire 3mm. thick. 



