storms*" Buffon says a sportsman told him he had often found more than twenty collected in the same hole t. We are informed by an intelligent friend, that he once found several wrens in the hole of a wall, rolled up into a sort of ball, for the purpose, no doubt, of keeping one another warm during the night; and though such a circumstance is only to be observed by rare accident, we think it very likely to be nothing uncommon among such small birds as have little power of generating or retaining heat in cold weather. This very circumstance, indeed, was observed by the older naturalists. Speaking of wrens, the learned author of the Physicæ Curiosæ says, They crowd into a cave during winter to increase their heat by companionship ‡." 66 Those who keep wrens in cages usually furnish them with a box, lined and covered with cloth, having a hole for entrance, where they may roost warmly during the night §. Yet even in keen frost the wren does not seem, in the day-time, to care much for cold, since we have in such cases frequently heard it singing as merrily as if it had been enjoying the sunshine of summer, contrary to the remark of White, that wrens do not sing in frosty weather T. During a fall of snow, sheep seem both to take advantage of natural shelter, and to huddle together in order to economize their animal heat; and they accordingly, during a snow-storm, always flee to the nearest shelter, though this is certain to end in their destruction, if the snow fall deep and lie long. It, * Illustrations of Brit, Ornith. i. 197. Ois. Art. Le Roi-telet. Multi uno specie in hyeme conduntur, ut parvus in tam minutis corporibus calor societate augeatur, p. 1249. therefore, becomes one of the most painful tasks of the shepherd, in such circumstances, to keep his sheep steadily in the very brunt of the blast. So at least we were told by an old shepherd, whom we encountered at night-fall the end of December, 1808, in a wild mountainous pass, near Douglas, on the borders of Lanarkshire, who was actually engaged in thus guarding his flock in as heavy a fall of snow as we recollect ever witnessing*. The Ettrick Shepherd, in a most interesting narrative, entitled 'Snow Storms,' in his Shepherd's Calendar, does not allude to this propensity in sheep; though it may be inferred that they had acted upon it on one of the occasions which he describes, from his having found a number buried under the snow by the side of a high bank, to which no doubt they had fled for shelter at the onset of the storm. Though sheep, from their mode of life, ought to be hardy, they exhibit an anxiety for procuring shelter well worthy of remark. It is mentioned by Lord Kamest, that the ewe, several weeks before yeaning, selects some sheltered spot where she may drop her lamb with the most comfort and security; and Mr. Hogg, in the volume just referred to, gives an instance in which a ewe travelled over a great distance to the spot where she had been accustomed to drop her lambs; but what was still more remarkable, a ewe, the offspring of this ewe, though removed to a distance when a few days old, returned to the same spot to drop her first lamb ‡. It is a very curious and remarkable circumstance, that many species which are solitary at one period of the year, are gregarious at another; and though it is possible to account for this in some instances, it becomes not a little difficult in others. It is obvious, + Gentleman Farmer, p. 15. Shepherd's Calendar, Chapter ou Sheep. * J. R. for example, that the winter nest of the gold-tail moth (Porthesia chrysorrhea) is constructed as a common domicile for a whole brood*, which in their young state can find enough of food though they keep together; but when they increase in size the following spring, and require a larger supply, they naturally separate, each to forage for itself. The fry of salmon and most other fish keep together in crowds in the early stage of their existence, not probably from any propensity to sociality, but because they are hatched about the same time at the head of the same pool, and as yet have no cause to be alarmed on account of the ravenous propensities of their companions. But this is very different from the congregating of birds after they have lived solitary for several months, as is the case with larks, linnets, the window and chimney swallows, and many others. The lark during the summer months is decidedly unsocial; for though we may meet with two or three pairs in the same field, we seldom find their nests near each other. They are not quarrelsome and pugnacious, like the red-breasts, but they seem to prefer a secluded spot to a crowded neighbourhood. The young larks, after leaving the nest, seem equally unsocial, and do not, like most nestlings, keep together in a band; but prefer to wander about the field by themselves, though this must increase the trouble of their parents in bringing them food. Yet these seemingly unsocial birds, as soon as the breeding season is fully over, flock together in numbers almost incredible, and have then been caught for the table in most countries of Europe from the earliest times, as in Greece, Italy †, and England. The numbers taken in France may be guessed at from the account *See Insect Architecture, p. 331. + Oppian in Ixeutica. On examining those floated out of the nest, they contained young perfectly formed, but dead *." The Virginian Rail (Rallus Virginianus, LINN.). Length, about ten inches. When the month of April has been more than usually wet, we have repeatedly found the nests of thrushes and blackbirds containing water, with eggs soaking in it, and we inferred that, from the impossibility of preserving them dry during continued rains, they had been abandoned by the owners as being spoiled for hatching. We have observed *Wilson, Amer. Ornithol, vii. 115. the circumstance too often to suppose the abandoning of these nests to have arisen from the accidental death of the birds *. The effects of moisture, as either beneficial or injurious, might be copiously illustrated, both in the hatching of eggs, and the germination of seeds. We shall content ourselves with one or two instances, in addition to those already mentioned. The red ant (Myrmica Rubra, LATREILLE), whose colonies are common in gardens, as well as those of most of their congeners, cannot well build their ingenious archways and vaulted chambers without the aid of dew or rain to moisten the earth which they knead for the purpose. But though, on this account, they rejoice in refreshing showers, they are well aware that their eggs would be injured or destroyed by the moisture; and if they have previously exposed them on the top of their nest to the influence of the heat during sunshine, they may be observed to display the utmost eagerness in carrying these into the dry chambers of the interior upon the first appearance of rain. A still more remarkable circumstance occurs, with regard to the eggs of a dung-fly (Scatophaga stercoraria, MEIGEN), which Réaumur found could not be hatched without a certain degree of moisture, although too much destroyed them. But Providence has furnished these eggs with two projecting arms at the outer end, to prevent their sinking too deep in the cow-dung in which the mother fly deposits them †. In the germination of seeds, it requires, in many cases, a similar moderate proportion of moisture to insure success, hence the value of a dry March, the usual sowing season, to our agriculturists and gardeners. We knew a Scotch gardener, the first year he was in England, commit a very excusable mistake See Insect Transformations, p. 44. * J. R. |