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Mounting Insects Whole.—In reply to J. H. W. (p. 163), respecting the method of mounting large insects whole for the microscope, though I am not aware what process is practised in mounting for the trade, I may describe the mode of proceeding which has been in my own hands very fairly successful. The great object, as many of the insects are of considerable thickness, is to prepare them to endure the requisite flattening without injury. For this purpose I soak them for a longer or shorter time in liquor potassæ, and it is in this part of the process that the chief danger lies. If the insect has not been immersed for a sufficient time, and is of hard texture, it is probable that the more convex portions, as the head and thorax, will split when pressed down by the thin glass cover. On the other hand, should the soaking period be extended too long, the object will be rendered so tender, that some of the limbs will very likely tear away during the necessary manipulation. As the time of immersion differs according to the firmness of the insect's covering, no precise time can be given. A hard beetle will require as many weeks' soaking as a soft spider would need days. Another evil attending too long a period in the solution of potass, is that the colour of the insect will be entirely discharged, and if mounted successfully, the result will be only a filmy effigy of the creature. I have an earwig so treated, which looks just like the ghost of an earwig according to the popular notion of ghosts' appearance (how difficult it is, by the way, to imagine the ghost of a far punchy man). If the right period is hit, the insect will be sufficiently softened to stand flattening (with care), without being rendered unpleasantly colourless. It should be pressed gradually between two glass slides in water, till the contents of the body are washed away and it is flat enough for mounting. It should then be arranged in proper position on one of the slides, and suffered to dry for three or four days; of course protected from dust. When quite dry, it may be immersed in turpentine, or floated over with the same under a glass cover, being careful that no water remains lodged in any of the limbs, &c. It should be kept covered with turpentine till all air-bubbles have disappeared, which will usually take place in three or four days, when the object may be mounted in Canada balsam in the usual manner. Bubbles will often disappear some time after the insect has been mounted, if the balsam is not too hard, and the object is kept in a warm place; and I believe many a slide has been hastily discarded from the presence of bubbles, when time and warmth would have made all right. A good-sized spider which I have mounted was so disfigured with air-bubbles that it was very near being thrown away; it was put on a warm mantel-shelf, and as it was observed after a few days that some of the bubbles had disappeared, it was suffered to remain there till every bubble was gone, which was not until nearly a month had elapsed. I fancy that the oscillating temperature of night and day, where a fire is regularly lighted each morning, is favourable to the removal of air-bubbles by alternately expanding and contracting them. I may perhaps add that I described this method of mounting insects whole in the third volume of "Recreative Science."—George Guyon, Ventnor, Isle of Wight.

Insects feeding on Wheat.—I have seen it stated that there have been collected in Europe no less than 27,000 species of insects preying upon wheat. Is there good reason for supposing that such an assertion is approximately correct?—A. O. F.

Sex of a Viper.—The gamekeeper of Wisley Heath, who is constantly seeing vipers, tells me that those with a light ground-colour are males, and those with a dark one females.—W. R. Tate.

The Hermit Crab.—The Hermit Crab does not always choose the empty shell of a univalve mollusk for its house, for on one occasion I saw a small hermit (Pagurus Bernhardus) which had fitted its hinder part into the empty hand belonging to the first right leg of another and larger hermit, the latter having previously exuviated. Soon afterwards I saw another and still smaller hermit, which had converted a fragment of the tubs of Serpula contortuplicata into a home. In both instances there were no empty univalve shells present, and therefore necessity became the mother of invention. These things took place in the Hamburg aquarium.—W. Alfred Lloyd.

Gossamer Spiders.—Although it is not very probable that many readers of Science Gossip can tell Dr. Lord a very great deal about Gossamer Spiders he does not already know, he may perhaps kindly reply to a few questions, and thus enlighten other folks. What are the tiny creatures doing in the air? Are they, like swallows, floating about in search of insects? I have seen the little voyagers in the spring, as well as in the autumn, darting out their gossamer filaments, and sailing up aloft like so many fairies. Since we are upon the subject of spiders, there is another question I want to ask Dr. Lord. Is it true that spiders (house spiders) are musical? Did the author of Verses to a Spider, which are to be found in the Anthologia Borealis et Australis, write from fact when he said the insect came down from the ceiling every day to hear him play, I wonder? I wish some young lady, who is not afraid of a spider (if there be so courageous a feminine), would try the experiment of playing her sweetest melody to one of Arachne's descendants, and give us the result. I am no musician, or I would solve the point myself.—H. W.

Light of the Lantern Fly (Fulgora lanternaria).—At a recent meeting of the Entomological Society, Mr. Evans read a letter from Belize on the subject of the luminosity of this insect, to the following effect:—"I have succeeded in my entomological researches about the lantern-fly. I had one given me, caught here, alive, and I saw it myself giving light. I kept it in a tumbler for about a day, and it sometimes did not give it, but at others it did."—Athenæum.

Fire-fly Light.—In reference to the discussion whether the fire-flies flash out their light simultaneously, Mr. Clark read the following extract from a letter at the last meeting of the Entomological Society:—"I can confirm your observation that the fire-flies, of the genus Aspisoma, flit at night in great numbers over low-lying, damp fields, chiefly near water, emitting light by short flashes, at intervals of three or four seconds, the majority keeping time with each other, as if in obedience to the báton of a leader. I think it is only the fire-flies of that genus who practise it. The numerous fire-flies common in Mexico and North America belong chiefly to the genera Ellichnia and Photuris, whose habits are different, so far as I have had opportunity to observe their congeners in Brazil."