Once a Week (magazine)/Series 1/Volume 4/Curiosities in natural history
CURIOSITIES IN NATURAL HISTORY.
There are a thousand curious facts and circumstances in natural history, in this and other countries, which escape being recorded either from their being thought too trivial, or from a want of a ready mode of communicating them.
For instance, it is well known to persons who have resided in Portugal, that the peasantry when they bring their eggs to market are so well aware, from their shape, that some eggs will produce pullets and others cock-birds, that they separate them when wanted to be set under hens, asking more money for those which will produce pullets than they do for the others, as pullets are in much greater request than cocks. This fact cannot fail of reminding our classical readers of the following passage in Horace, who, curiously enough, seems to have been aware—like the good women of Portugal—of the difference between eggs producing pullets and others of a different shape, hatching cocks only, and giving his preference to the former:
“Longa quibus facies ovis erit, illa memento,
Ut succi melioris et ut magis alba rotundis
Ponere: namque marem cohibent callosa vitellum.”
Satyra iv. liber ii.
Which may thus be translated: Mind and serve up those eggs that are of an oblong make, as being of sweeter flavour and finer colour than the round ones; these, from being tough-shelled, contain a male yoke.
An interesting circumstance was lately communicated to me by an agreeable and hospitable family in Surrey, with whom I was on a visit, and who had previously resided for some years in Oporto. The fact was vouched for by three persons there present, all of whom had witnessed it.
A room in a house of one of the principal ecclesiastics in Oporto was set apart for the reception of a quantity of maize, or Indian corn, which had been thrashed out. It is well known that each of these grains of wheat must be at least as heavy as three or four grains of our common wheat. On visiting this room one day, its owner perceived a grain of the maize suspended from the ceiling of the room by a single thread thrown out by a spider, and which was, from time to time, gradually but slowly drawn upwards. Surprised at this very unusual sight, he invited several persons to witness it, and amongst others my three informants. What the motive of the spider was, in endeavouring to secure this heavy grain of wheat, and draw it up to its nest on the ceiling, I will not attempt to account for, as it is so contrary to the usual habits of these interesting insects; but it is a curious fact that a single thread thrown out from the body of a spider should be able to bear the weight it did.
It has long been a matter of doubt amongst naturalists as to the food of the glow-worm. Cuvier suggests that they are probably carnivorous, and it would appear, from recent observations, that he is right.
The larvæ of the glow-worm are very voracious in their habits, and it is now known that they feed on snails and not upon plants. It is not very probable that perfect insects feed much. If it does, it would probably be on some animal substance, such as decayed worms, &c.
The male glow-worm only is winged, and has two spots of bluish phosphorescent light on the belly. The greatest luminosity is given to the female:—
“To captivate her favourite fly,
And tempt the rover through the dark.”
Some time after the female has laid her eggs, which are very numerous and large, spherical, and of citron-colour, and shine in the dark, the light disappears in both sexes. Glow-worms crawl slowly, and are able to shorten and lengthen their bodies.
It has been suggested that the phosphorescent light in these insects is for the purpose of attracting small flies to it, on which the glow-worm feeds. This is certainly a mistake, though flies have been observed to hover over the light. So strong is the light of another species of glow-worm—the Lampyris noctiluca, found under juniper, rose-bushes, &c.—that two of them placed in a glass give sufficient light to read by.
The male glow-worm hovers over the female in the twilight.