Page:Hardwicke's Science-Gossip - Volume 1.pdf/183
A curious Blight.—On Sunday last I noticed many little floating particles of wool or cotton, as it seemed, in the garden, in a bright sunshine. On looking closer, I discovered that they were insects. I captured several and put them into separate pillboxes. On looking at them some hours after, I found that there were also in each box some ten to fifteen other fawn-coloured insects, much more minute and wingless. I at first thought they might be parasites, hidden before in the cotton covering; but to-day, having again seen some specimens, I examined one under a microscope, and found that they were young, extruded from the parent; at first motionless, with antennæ and legs placed chrysalis-wise, but in a few minutes becoming active. I have never noticed this insect before; and only now on these two days. I can discover none on any plants in the garden, though they approach in character to what is commonly termed "blight." I enclose two specimens, with some of the young, which I hope will not get quite dried up. If you can tell me what they are, I should feel much obliged: they may be common, but I never before observed them.—H. W. Livett, M.D.
[The species sent is one of the Aphidæ, nearly allied to the woolly American blight (Aphis lanigera). It belongs to the genus Pemphigus, having four simple oblique veins to the fore wings, none of them being furcate.—J. O. W.]
Bees' Remains. "A. O." Answer.—I can easily explain the cause of the death of the humble-bees, having as a boy often found, more especially the large red-tailed humble-bee, crawling on the ground, disabled. On examination, I have invariably found them infested, and completely eaten into by a dark-coloured louse, which always chose the back of the bee for its point of attack. I have found living bees with holes large enough to admit a pea, and containing three or four of these parasites. Our belief was that the bee was eaten in this unvarying manner for the sake of its "honey-bag," the hole being always made in its immediate proximity.—R. K.
Aquarium Query answered.—In reply to "G. R. B." (page 143), the best remedy, and also preventive, against growth of the plant he describes, is three or four snails, either Trumpet (Planorbis corneus) or Pond Winkles (Paludina vivipara); they are both capital cleansers. Tadpoles are also of benefit; but not to the same extent. I am enabled to speak from experience, having been very successful with my aquariums for the past two years, although previously I think I had as many accidents and misfortunes as any one.—Thomas Armstrong.
[The same advice is given by G. M. Ruck.]
Exotic and British Diatoms.—Mr. Kitton (page 140) seems to be under a mistake in supposing the Coscinodiscus radiatus to be exclusively an exotic diatom, as I have found it plentifully in a cave attainable only at lowest water, in the face of the rocks about ten miles south of Aberdeen; more sparingly along the coast in the neighbourhood. Enclosed is a slide (I am sorry it is not a very clean one) showing the proceeds of one dip in a washing therefrom.—H. Ambrose Smith, Aberdeen.
Beech-trees.—Why is it that these trees injure all others encroaching upon them, but are seldom, if ever, injured in return, and will allow nothing to thrive under them?—A. H.
The Golden Bloomeria.—A friend of mine, who has lately returned from California, allows me to take an occasional peep at his note-book. I there I alighted on a short account of what I should imagine to be a very lovely bulbous plant, called the Golden Bloomeria, and I should much like to know if it has been introduced into this country by any botanist. The specimen of the blossom I saw was dried, and it had consequently lost the bright golden hue which marks its beauty when growing. (Apropos of dried flowers, I saw a remarkable group, mounted with their natural colours, exquisitely preserved, at the grand fête, on Saturday the 10th, at the Horticultural Gardens); its bloom is wonderfully lasting, I am told, continuing in flower for a month or five weeks ere it begins to fade; but I believe it is scentless. The bulb was first found in New Idria, and has been classed by a Californian florist with liliaceous plants.—Helen Watney.
White Sparrows in Smoke.—I am informed, by an eye-witness, that some time back a white sparrow was seen to fly backwards and forwards through the smoke of a factory chimney; and this it continued for several days, and then disappeared as suddenly as it came. I also am well acquainted with a glass-manufacturer, who informs me that for several weeks he observed a white sparrow flitting about the works undeterred by the constant noise and smoke. Can any correspondent favour me with information as to whether the white sparrow has a predilection for smoke, and prefers to live in smoky districts; also, if cases similar to the above have been noticed?—H. A. A.
Sea Anemones Dividing.—I had a very fine Anthea in a small sea-water aquarium for some months. One night I left it on a piece of rock, and to my surprise, the next morning, I found two in the place of one, on the same stone, with about the space of half an inch between them. They were both fully expanded, and lived for some months after; indeed, till I left home. Are Anteas in the habit of dividing themselves in half? and what can have been its motive? I should mention that the two Antheas were about equal in size.—L. S.
Black Beetles.—Can any one tell me an effectual method of getting rid of black beetles in a house which has been swarming with them for many years, in spite of several common remedies,—poisons, &c., of which they seem to grow shy after a time?—A. H.
White Corn Poppy.—I recently found a splendid pure white variety of Papaver Rhæas in a field between Stoke Newington and Hornsey; the petals were pure paper-white, with a purple-black blot at the base of each petal, in all other respects exactly the same as the ordinary red form.—W. G. Smith.
Stream Bubble-shell (Physa fontinalis).—Many of your readers are doubtless aware of the power possessed by this mollusc of letting itself down from the surface of the water by means of a thread which it forms for the purpose. As perhaps only a few may have had the opportunity of witnessing the phenomenon, I will attempt to describe it. Happening to look along the surface of the water in a small aquarium, I noticed a small circular spot about half a line in diameter. The centre was depressed and funnel-shaped, while to the under side was attached a thread, at the lower end of which was the physa. I touched the floating speck with a stick, to which it adhered, and I lifted the mollusc out of the water by the thread.—C. A.