Page:Hardwicke's Science-Gossip - Volume 1.pdf/229

Eel-like Animalcules.—In some animalcule water which I prepared with hay, by exposing it to the hot sun, I found a species of Infusoria, which I have never seen noticed in any book. Most likely it is common enough to many, but it is quite new to me, who am only a novice. With ¼-inch object-glass they are just discernible, and have the appearance of live hair, about half an inch in length. They wriggle themselves slowly along, moving like an eel, from right to left, and never seem to turn round, but go gently across the field of the microscope, and then return with either head or fail first. Could any of your readers inform me what they are, and what is their name, &c.? From what I noticed in their movements, I imagine that they feed pretty freely on the Polygastrica.—J. S.

Doubtless they are Vibriones.—T. K.

Gossamer Spiders.—In reply to H. W.'s question relative to Gossamer spiders feeding in the air, and House spiders having a taste for and love of music. In the first case I do not think there is any evidence to show that the spider can by any possibility catch its prey, save by pouncing on it, as in the Hunting spiders, or trapping it, as do all web-spinners, mason-spiders, and others of like mechanical craft. The web thrown out is solely for the purposes of transport, a simple yet beautiful contrivance to enable the tiny creatures to disperse, and thus obtain a better chance of thriving, in the great struggle for existence. I very much question the House spider's having the "least taste in life" for music. In the first place, it is doubtful whether the spider can hear at all; and granting it did, the auditory organs would hardly attain a degree of organization (where we have only the heterogangliate nervous system) compatible with power to detect and appreciate modulations of sound. We must seek the solution of the mystery—that is, in the first place, if it can be proven that House spiders ever do exhibit any fondness for music (I do not believe they do)—in the vibration caused by the instrument inducing the spider to come and see what great insect is creating such a disturbance. Hammer on a wall or shake a piece of furniture near a spider's trap, and nine times out of ten, be will come to see what it means; but he simply feels the vibration. Such a solitary savage never could have music in his soul, and admirably verifies the truth of the couplet:—

In a future number of Science Gossip I purpose adding my mite about North American spiders.—J. K. Lord.

Aquarian Difficulties.—E. T. S. refers to aquarian difficulties. The one great cause of nonsuccess in the management of aquaria is the overexposure of them to strong light. The second is the non-removal of dead matter; and the third, the too miscellaneous nature of the plants and animals introduced. I do not find any difficulty with either fresh-water or marine aquaria.—T. P. Barkas.

Guano.—Can any of your correspondents tell me where I can obtain sufficient guano (say a quarter of a pound at least) to experiment upon for Diatomaceæ, as it generally contains more fossils than the earths or bergh-mehl?—J. H. W.

Sea-Anemones Dividing.—Instances of spontaneous division in Sea-Anemones are by no means rare; indeed, Mr. Gosse seems to think that some species (amongst others the Plumose Anemone) only increase in this manner. With the author, I have myself witnessed the operation, In Mr. Gosse's words (Brit. Sea-Anem., p. 169), "The fission begins at the margin of the disk, and gradually extends across and downward, until the separation is complete, when each moiety soon closes, and forms a perfect animal." With the Plumose Anemone and some others, the division is of a different character. Parts of the disk are torn off and remain adhering to the original resting place of the creature, whilst the Anemone itself sails off to some more comfortable quarter. The detached fragments then gradually form into small Anemones.—C. A. Goodhart.

Sea-Anemones Dividing.—Your correspondent E. T. S. appears to think that Anemones do not increase by division. I have kept Anemones in the same tank, without any change of water, for five years, and have seen them increase by division, by generation, and by ejection from the mouth. If he cuts a healthy Mesembryanthemum perpendicularly into two parts, by means of a sharp knife, he will find that the two portions will become perfect Anemones in a few days. The act appears cruel, but I am inclined to think that Anemones do not feel pain, and that all these motions are automatic.—T. P. Barkas.

E. S. writes us that it is impossible for two Anemones to have been contained in her tank, as suggested by E. T. Scott.

W. R. Adams confirms the fact of Sea-Anemones dividing, from personal observation on several occasions.

Fresh-Water Aquaria.—If F. C. will carefully read "Hibberd on Fresh-water Aquaria," and attend to his instructions, all his difficulties will vanish. I have kept fresh-water aquaria for years, water unchanged, without either trouble or difficulty. There are not any aquaria without Iufusoria, but if the tank be not subjected to too much heat and light, Infusoria will not appear in excess. Dried beef, cut into very small particles, is the best and most convenient food for fishes, and they ought to be under-fed rather than over-fed. Charcoal is not necessary to keep the water clear, and caddis worms are best left in their native ponds. The best plants are Vallisneria spiralis, Anachares alsinastrum and Chara vulgaris.—T. P. Burkas.

Volvox Globator.—Your correspondent T. A. will find that the cause of the motions of Volvox Globator is said to be the action of cilia. I have gathered myriads, and examined thousands, but never succeeded in observing cilia on any of them. That may have been my fault in manipulation, but as the ciliary theory has been rejected in the ease of Diatomaceæ, may it not ultimately be ascertained that the motions of Volvox Globator are produced otherwise than by cilia?—T. P. Barkas.

White Earwig.—The other day, I found among some gooseberries, a perfectly white earwig, the eyes being black. I have preserved it in spirits; thinking it very rare. I thought I should like to know whether it is so or not, and whether any of the readers of Gossip have met with anything of the kind.—R. F. M.

[They are occasionally met with.—Ed. Sc. G.]