HARDWICKE'S S CI EN C E- GO S S IP. 



261 



NOTES AND aUERIES. 



How TO Cleau a Pond.— H. B. Rutt won't, find 

 his fish so healthy if he were to get rid of the 

 vegetation. Tiie best way to keep it down is to 

 pnt a number of water snails into the pond, 

 and draw the superfluous vegetation out with a fine 

 hand net or rake, or something of the kind. At 

 least, I find this the best way.— £". T. Scott. 



The Coloxjks of LspiDorTERA, pp. 175, 237.— 

 Mr. Lefroy seems somewhat to have misunderstood 

 the paragraph to which he refers. I did not say the 

 "metallic lustre" of the Papilimiida? was owing to 

 scales of different shades being placed transversely; 

 but tiiat possibly this might be the cause of that " re- 

 markable change of colour" which many exotic 

 specimens exhibit when held in certain lights or 

 positions,— a supposition which examination, how- 

 ever, with the microscope does not substantiate. 

 The question is an interesting one. Perhaps some 

 of the readers of Science-Gossip may be able to 

 account for this burnished appearance, and the 

 change of colour ?Lho.— Joseph Anderson, Jmr. 



How does the Spider weave its WuBp-^In 

 a recent number, I was much interested by readiu? 

 an article on the Wood Spider and its habits, and 

 it occurred to me that some of your readers might 

 be able to answer me a question which has long 

 puzzled me, and which remains a mystery to nie 

 still. I will first describe wliat I saw, and then 

 ask the question. Two or three years ago, I was 

 walking by the side of a small mill-stream, when my 

 attention was arrested by a very large spider's web 

 stretching across the stream from bank to bank, 

 and attached to the stems of grass and other herb- 

 age. The stream was not less than three feet in 

 width, and the web itself would not be less than 

 four, by six feet in length. The web itself was 

 constructed on the mathematical principle, and 

 resembled a cart-wheel in general outline, a number 

 of diverging spokes proceeding from a central point 

 or nave, and these spokes were united by concentric 

 circles of threads about a quarter of an inch apart, 

 over the whole structure. The domicile of the 

 spider was exactly in the centre of the web and 

 over the middle of the stream, and, when I saw it, 

 the spider was hanging by a thread about a foot 

 from the running stream. The^ spider itself was 

 about the size of a dried marrow-fat pea of the same 

 colour. Now this remarkable sight excited my 

 wonder and curiosity to comprehend how an aninial 

 that, neither flies, leaps, nor swims, could accomplish 

 such a feat, and I am still in the dark as to its mode 

 of operation in making its web. — (?. C. 



The Squirrel. — I little thought the storm 

 growing out of a mild effort to stay hasty judgment 

 against our little red squirrel could have echoed a 

 murmur across the Atlantic ; our cousin, however, 

 will, I trust, excuse me if I doubt the cogency of 

 his evidence. He has never seen, it appears, the 

 little animal in dispute in its native haunts : his 

 observations refer to the grey squirrel, a much 

 larger, and, it would seem, bolder creature, — 

 altogether a different species; and unless we are 

 prepared to accept the Darwinian doctrine, the 

 two can have no common blood in their veins. But 

 they are classed together as squirrels ? and analogy 

 should go for something? AVell, but. until of late 

 years, men and bats were so classed : Homo sapiens. 

 Homo vespertilio. Will analogy help the hope that 



\ men may and will, so soon as the necessity is urgent 

 I enouf^h, adopt the charming mode of locomotion of 

 I the bat. Elongate their fingers to some ten feet, and 

 ' grow a web between them, and it is done. Mr. 

 Abbot calls my attention to p. 237, Science-Gossip, 

 1871, for the purpose of proving that our squirrel 

 should be a match for the pheasant, because his 

 " grey chap " (about the size of a half-grown rabbit) 

 could " bamfoozle" (whatever that may mean) our 

 "pheasant, provided the nest of the bird was in a 

 tree, and on branches that would give the nimble- 

 footed fellow any chance at all to hold on," As, 

 however, our pheasants do not make nests in the 

 branches of trees, I need not trouble you, sir, with 

 any remark upon an event which, in the present 

 state of things, is impossible. I must now bid fare- 

 well to our ruddy little friend, only hoping that, 

 wherever the adroitness of his movements may 

 admit of a doubt whether the suspected &^g he is 

 carrying may not be a walnut or a chestnut, he may 

 Lave the benefit of it. — George Cox. 



Ants. — I have noticed that several of your cor- 

 respondents have asked for a way to get rid of ants. 

 When in the north of Italy last winter, I noticed 

 one morning that there were a great number of 

 very large ants on the floor of my bedroom, which 

 was on the ground floor. I at once spoke to the 

 proprietor oi^ the hotel about them, and he said he 

 would very soon get rid of them. We found the 

 nest, which was just outside, and he poured about 

 half a pint of petroleum and water in equal quan- 

 tities into it, and he said I should be troubled no 

 more, for the ants would never go back to the nest. 

 In an hour or two there was not even a stray ant 

 to be seen ; and although I remained at the hotel 

 for more than a month, I never saw an ant either 

 enter or leave the nest again. Should any of your 

 correspondents try this method, perhaps they will 

 let you know with what result, a mouth or two 

 hence. 1 have no opportunity of trying it myself, 

 as I am not at all troubled with ants in my garden. 

 —C. E. H. 



Abundance of the Large Heath Butter- 

 fly. — In a bad butterfly year like the present, it is 

 agreeable to see even a common species in full force 

 on the wing; and I am glad to record that the 

 Large Heath {Ephinephile tithonus) is as plentiful 

 as usual in Kent and Surrey, though rather later 

 than its average in appearing. This is a remarkably 

 tame species, and when fluttering about the bramble 

 bushes, it may easily be caught with tiie hand. The 

 Large Heath has a habit, like some of the skippers, 

 of turning half round after it has alighted upon a 

 leaf.— J. R. S. C. 



The Cuckoo in October.— On the 3rd of 

 October,- — a day to be remembered in many places 

 by reason of severe hail-storms, thunder, and 

 lightning, — I observed a cuckoo flying into a wood, 

 and it struck me as being very singular to see this 

 visitor so late in the season. I should imagine that 

 the bird does not intend to migrate. Does this 

 denote a mild winter ? — Fred. Anderson. 



Keeping Chrysalids. — In reply to a query by 

 "Mabel Green," as to keeping Chrysalids, I have 

 found the following a good plan : — Procure a strong 

 wooden box, — a convenient size is about 18 inches 

 square ; screw two pieces of wood 2 inches wide 

 on the inside of the lid, across the grain, cut out 

 part of the wood between them, and replace with 

 perforated zinc on strong gauze. Fill the box to a 

 depth of 6 inches, as you would a feru-Gase— viz.. 



