494 



NATURE 



[Afarc/i 25, 1880 



The nearer the form and habits of man in his most primitive 

 stage resembled those of the apes, the more in all probability 

 would his habitat or range have been identical with theirs. 

 Therefore an examination of miocene or early pliocene deposits 

 along this line and its diverging branches would scarcely be 

 unattended with success in producing many fossil remains of very 

 primitive or Simian man. 



I trust I have said enough to indicate the direction which 

 inquiry ought to take as far as present evidence goes, and I hope 

 that a gigantic combined effort may ere long be made by all 

 naturalists and all lovers of truth to attempt in a downright 

 earnest manner the solution of this great question of the origin of 

 man. W. S. Duncan 



The Stone in the Nest of the Swallow 



Would any of your readers be kind enough to give me some 



information about the origin of the fable to which Longfellow 



refers in the following passage of his "Evangeline," Part I., at 



the end : — 



" Oft in the barns they climbed to the populous nests on the rafters, 

 Seeking with eager eyes that wondrous stone, which the swallow 

 Brings from the shtre of the sea to restore the sight of its fledglings ; 

 Lucky was he who fcund that stone in the nest of the swallow ! " 



Leiden,. March 19 P. P. C. Hoek 



Carnivorous Wasps 



Sir David Weddekbukn's inquiry (Nature, vol. xxi. p. 

 417) reminds me of my experience on this subject. Many years 

 ago I was examining an apple-tree, when a wasp alighted on a 

 leaf which formed a caterpillar's nest neatly rolled up. The 

 wasp examined both ends, and finding them closed, it soon 

 clipped a hole in the leaf at one end of the nest about one-eighth 

 of an inch in diameter. It then went to the other end and made 

 a noise which frightened the caterpillar, which came rushing out 

 at the hole. It was immediately seized by the wasp, who, finding 

 it to 3 large to cany off at once, cut it in two and went off with 

 his 1 ame. I waited a little, and saw the wasp come back for 

 the other half, with which it also flew away. 



After witnessing such evidence of intelligence I have had a 

 great respect (or wasps, and gave orders to my gardenersnever 

 to destroy one. 



I gained some further evidence 06 their carnivorous taste when I 

 once took my children to Switzerland for a holiday, and on a butter- 

 fly hunting expedition. We had spread out the day's find in the 

 evening, and next morning I placed the boards in the sun to dry. 

 On looking at them some hours later 1 found nearly all the 

 bodies gone, only the thorax and wings left ; and while examin- 

 ing them a wasp alighted on the board, and I soon proved that 

 he was the culprit. 



I have no doubt that wasps are most serviceable to gardeners 

 by destroying caterpillars. R. S. Newall 



March 21 



Intellect in Brutes 

 Some lime since I observed the following conduct of two 

 spiders, which will show how they sometimes overcome diffi- 

 culties in the way of capturing their prey. A rather large house- 

 spider had its web in the corner of a room, and during the 

 summer it feasted upon the insects that were unlucky enough to 

 le caught. One evening I noticed a large dipterous insect strike 

 the web ; the spider darted out and succeeded in fastening me 

 lout of the fly. The spider then kept running back and forth, 

 attaching a thread to a wing, then to a leg, which was scon 

 broken by the violent efforts of the fly to release itself. The 

 spider wnrUrl without ceasing for over half an hour to secure its 

 victim ; it then quitted operations, and retired to a distant corner 

 of ils web. After seeming to rcllect lor a v\ hile what was I est tu 

 do, it left the web, went up the wall eight or ten inches distant, 

 aid entered a crack in the ceiling. I supposed at the time that 

 the spider had been injured in the scuffle, but what was my sur- 

 prise after a few moments to see the spider coming back, and 

 close behind another followed ; the two went on the web near 

 the centre, and stopped side by side, apparently consulting as to 

 the best mode of attack. Then at the same instant both spiders 

 d.uicd upon the insect, one towards the head, the other towards 

 the tail, bo rapid were their movements I could hardly follow 

 them. In a short time the insect was securely fastened. Both 

 spiders then leturned to the centre of the web. Soon after the 



friendly spider went to the crack in the ceiling, while the other 

 enjoyed the feast alone. A. M. 



North Manchester, Indiana, U.S., February 25 



Diatoms in the London Clay 



Your correspondent, Mr. W. H. Shrubsole, inquires where 

 sections may be seen in the lower part of the London clay. lie 

 will find a good exposure in a brick-yard, half a mile south-west 

 of Roydon Station on the Great Eastern Railway ; in another at 

 Ilndham Ford, on the Buntingford branch line, and several in the 

 brick-fields near bishop Stortford. In all these sections the lowest 

 part of the London clay may be seen, resting upon sands, or 

 loams, of the Reading series. Upon direct application, or 

 otherwise, I shall be happy to supply Mr. Shrubsole with further 

 information. W. H. Penning 



Granville House, Finsbury Park, N. 



VISUALISED NUMERALS 



SINCE I addressed a preliminary memoir to you on 

 this subject, 1 so much curious matter has reached 

 me that I trust you will permit me to state my views 

 afresh, and to deduce some inferences. Many of my 

 readers do not and cannot visualise, and few have the 

 habit in a pronounced degree. I must, however, beg 

 them not to consider their own minds as identical with 

 those of every other sane and healthy person. Psycho- 

 logists ought to inquire into the mental habits of other 

 men with as little prejudice as if they were inquiring into 

 those of animals of different species to their own, and 

 should be prepared to find much in many cases that is 

 quite unlike their own personal experience. 



Persons who have the tendency to use mental pictures 

 as the symbols with which they carry on their processes 

 of thought, do so especially in the case of numerals. 

 Thus, when they think of "six," the figure "6" arises 

 before the mind's eye more readily and vividly than the 

 sound "six" echoes in their mind's ear, or than any 

 other perception of that numeral manifests itself. Now 

 the peculiarity that I accidentally found out is this, that 

 about one out of every thirty males, or fifteen females, 

 not only visualise their numerals in this way, but also 

 invariably assign to each of them a definite place in their 

 mental field of view, where it seems to have a home. 

 Thus 6 may always lie low down to the left, 7 may be 

 found a little higher and more to the front, and so on. 

 It follows that whenever these persons think of a series ol 

 numbers, as 1, 2, 3, 4, 5, &c, they ahvajs appear to the 

 mind's eye as ranged in a definite pattern or "form.'' 

 This form is stated in all cases to have been in existence 

 at the farthest period to which recollection goes back, 

 though in many cases it has insensibly grown until it 

 included the higher numbers and even negative values. 

 It is usually of a rambling irregular shape, and though 

 constant for the same person, it differs very greatly i;i 

 different persons. It may consist of a row or rows of 

 faintly marked figures, suspended in the air or lying on 

 a hazy ground, and when the mental eye travels along the 

 row, each as it is looked at in succession becomes for the 

 moment vivid. Or it may consist of a faint line with 

 nothing on it, along which the eye is wont to travel until 

 it reaches the place where the figure it wants is known to 

 reside, and then the figure starts into sight. Or it may 

 be a haze penetrated by faint lines. Or there may be no 

 figures at all in the line, but only dots denoting position. 

 The planes on which the forms lie slope in some cases up 

 to the heavens, in others down to an immeasurable abyss. 

 They often start a little below the level of the eye and 

 rise gently upwards, reminding one of what the appear- 

 ance of objects on a table would be to a child whose head 

 hardly overtopped it. All these forms can be drawn in a 

 way more or less satisfactory to those who see them, and 

 I have now received nearly eighty drawings, in about 



' Natirb, vol XX'. p. 252. 



