Page:Hardwicke's Science-Gossip - Volume 1.pdf/254

Ichneumons and Vanessa.—In your January umber, p. 15, "The Entomologist" says that the "small Tortoiseshell Butterfly" is free from ichneumons. I send you a paper, the inside of which is completely eaten out by them, also one of the flies which crawled out of it, and some empty ichneumon-cases which I found close by. This is the second I have found in the same place.—E. W.

Wasps.—In Greece, a large wasp, marked on th abdomen with alternate rings of black and yellow, is very fond of grapes, and therefore a foe to the gardener, who gives them no quarter. It sucks the juices from the grape as soon as it is ripe, leaving nothing but the seed and shrivelled skin. This wasp also destroys numbers of spiders, which it treats like the grapes, rejecting the epidermis. Many severe and protracted combats ofttimes take place before the spider yields to its more powerful antagonist. I have observed that in pursuing spiders, the wasp rarely flies, but almost invariably runs after its prey. It attacks spiders without reference to size, and kills them by stinging. Does this happen in England?—J. B. Hay, Athens.

Birds' Eggs.—Some time since, while searching for birds' eggs, I found a Catbird's (Turdus avidus) nest, containing two full-sized eggs, and a third, similar to the others in colour, only of the size of a pea. How to account for this I know not. But it is well known that hens often lay eggs much smaller than the average size, sometimes not larger than a robin's; may not birds do the same? This is the only case which has occurred to my knowledge. Have any such instances occurred in England?—J. B. Hay, Athens.

Black Beetles.—For the information of "A. H.," I send you the following method of destroying them, which I have found more effectual than any of the advertised remedies:—Take one or more shallow glazed dishes (say three or four inches deep), and about half all them with common beer, or warm water with a little ginger or nutmeg grated in to make it smell; a little treacle also is a good thing. Place the dishes in their haunts, and put some bits of wood or something against the sides of the dishes for them to creep up (paper will not answer, as the noise of running up it appears to alarm them). The beetles and crickets being very thirsty creatures, and always ready for their "drops," get into the liquor and cannot get out again.—J. Goodyear.

Guide to the Conservatory.—A. H. wishes to know a book for the care of a "conservatory," containing what flowers are the best to plant in pots and vases, so as to keep up a succession of flowers all through the year. How hot should a conservatory he kept during autumn and winter? Please state the price of book.

Black Ants.—Under July 24th, I have a note in my pocket-book to the effect that I noticed on that day a number of large black ants crawling about the streets of Camberwell and Kennington. I should like to know whether any one noticed the same in any other part of London, and what was the cause of it.—W. R. Tate, 4, Grove Place, Denmark Hill.

Poduræ Phosphorescent.—Is it known that any species of the genus Podura (Linn.), order Thysanaura (insecta), is capable of emitting a phosphorescent light? I have good reasons for believing that one which I have met with is so capable. The head has a vertical movement, the centre of motion; tail about two-thirds length of body; compact, silvery-white skin; slight annular markings on back. If worth while, I can supply live specimens and further particulars.—H. M.

Pollen of Valerian.—Have any of your readers observed how beautiful the pollen of Valerian is? if not, I advise them to do so. It requires rather a high power.—W. Gibson.

Diameter of Lenses.—Can any of your oblige me with the diameter of the compound lenses used in making ⅛-inch object-glass, and the focus of each compound lens in it, and the diameter of the aperture?—E. T. S.

Parasites of Parsnip.—The leaves of the wild parsnip are very much mildewed; but, besides the usual round conceptacles, there are some others, consisting of an immense number of transparent bodies in shape very much resembling the blade of a reaping-hook. What is their name and purpose, as I don't see them mentioned by M. C. Cooke in the papers on fungi in Popular Science Review.—E. T. S.

[Specimens should have been sent.—Ed.]

A New Silene.—I extract the following from the Guardian of August 23rd:—"A specimen of a new plant, the Silene dichotoma, has been found near Painswick, Gloucestershire. It is a native of south-eastern Europe, and must have been introduced accidentally." Can any of your readers give me any additional information regarding the appearance of this "distinguished foreigner" in this country?—B.

Appendages to Water Beetles.—I have frequently observed of male specimens of Dytiscus marginalis (both alive and dead) a quantity of pear-shaped excrescences firmly attached by the small end to the underpart of the head of the insect. These excrescences are of a blood-red colour, and when squeezed, a red liquid exudes. Can you, or any of your correspondents, tell me what they are?—E. Ragonot.

Volvox Globator.—Will you kindly allow me to say, in answer to T. P. Barkas's reply to my query, I am quite aware that it is generally stated the notions of the Volvox Globator are caused by the action of cilia; but I have examined some thousands in every stage, and have been usable really to observe cilia; and many of my microscopic friends have also studied it, and none of them have been more successful than I have. I was in hopes my query would have drawn a reply from some one who had also devoted some time in examination of this very beautiful and interesting microscopic object, and who could, from observations, give a new theory respecting the cause of its revolutions. T. P. Barkas's remarks are really not a reply to my question. A great many of your readers are, I know, equally interested as myself in this, and quite as disappointed that my query has not drawn forth a better reply to it.—Thomas Armstrong.