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nest, to see the eggs snugly concealed beneath. The question immediately arises, Did the mother bird thus cover the eggs herself, and if so, for what purpose was it done? "If you be not too impatient, (a state of mind exceedingly adverse to accuracy and originality,) you will endeavour to ascertain whether the covering of the eggs was peculiar to this individual, or common to the species, by repeated observation, as frequently as opportunity offers; or, if pa tience fail you for this, such books as you have access to may be consulted. Look into Linnæus, and all you find is, that this bird builds a floating nest of grass and reeds.' Latham says, 'the nest is made of water-plants among the reeds, and close to the surface of the water, floating independent.' Willughby, Ray, and Brisson, say not a word about the nest. Fleming, says the nest is in marshes of aquatic plants, and made so as to float.' They breed,' says Goldsmith, among reeds and flags, in a floating nest, kept steady by the weeds and margin.' They 'construct their nest,' says Griffith, evidently copying Temminck, with rushes, &c. interlaced, which they attach to the stems of reeds, resting it on their broken tops, or suffering it to float.' Nest large,' according to Jennings, 'made of aquatic plants not attached to any thing, but floats among the reeds and flags penetrated by water.' Belon, who is followed by Gesner, Aldrovand, Jonston, and M. Drapiez, says, 'it nestles near the ground upon some turfy clump in a marsh, difficult of access.' our large pools,' says Buffon, they build with reeds and rushes interwoven, and the nest is half dipped in the water, though not entirely afloat, as Linnæus asserts, but shut and attached to the reeds.' Wood subsequently adds, in a note, 'they construct a floating nest of reeds.' "They build their nests,' says Hill, floating and loose among the flags ;' and, being altogether unconnected with the reeds among which it floats, it sometimes happens that it is blown from among them into the open lake. In this situation the owner, like a skilful pilot, it is said, steers the nest into a safe harbour, by passing her feet through it.'

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• On

"In all these various notices of the nest in question, by the well-known naturalists thus consulted, there occurs no mention of any covering of the eggs, though the inquiry

has brought under notice some other curious particulars, which, no doubt, a young and ardent observer will be anxious to verify on the nest itself, from which his bookresearch originated. Some of the authors, it has been seen, assert that the nest floats on water, nay, that it is purposely built to float by the mother bird; while others make no mention of its floating, and some expressly deny it. In a supposed case like this, it may, perhaps, be deemed premature for me to decide; but the nests which have fallen under my observation, agree with those originally described by Belon, in being built on raised clumps in marshes, or at least so supported by water-plants as not to be intended to float. That in consequence of floods these nests may, by accident, have been found floating, it would be wrong to deny, though there can be little doubt that Linnæus, who was much too credulous of wonders, magnified a chance occurrence into a general rule. The story of the mother bird navigating her nest when it has been carried away by a flood, is altogether incredible; for the nest is not only constructed of a bedding of reeds, rushes, and other water-plants, more than a foot in thickness, but the feet of the bird are so broad and clumsy, that they could not be thrust through it without entirely destroying its texture.

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"Pennant, however, seems to believe this nonsense, for he adds to the account- In these circumstances the halcyon's nest, its floating house, fluctivaga domus, as Statius expresses it, may in some measure be vindicated.' The same author also is more particular about the floating of the nest, which he says is built near banks in the water, but without any fastening, so that it rises and falls as that does. To make its nest, it collects an amazing quantity of grass, water-plants,' &c.: and he adds, 'it should seem wonderful how they are hatched, as the water rises through the nest and keeps them wet; but the natu ral warmth of the bird bringing on a fermentation in the vegetables, which are full a foot thick, makes a hot-bed fit for the purpose.' If our young student, upon reading this very questionable doctrine, turn to this Dictionary, page 127, he will learn that Colonel Montagu uniformly found the nests cold, and that, taking into account the chemical

principles of fermentation, it was impossible they could be

warm.

"But Pennant also mentions a circumstance of much more interest in reference to the original inquiry, when he says that this bird lays five or six white eggs, and always covers them when it quits the nest,'-the very point to ascertain which the research was begun. With this authority, supported as it is by Montagu, most students might rest satisfied, but the ardent naturalist never arrives at any conclusion like this, without bringing all the facts within his knowledge to bear upon it, in order to elucidate connecting causes and consequences; for the fact being ascer tained of the mother bird covering her eggs, it becomes interesting to inquire why she does this.

"It is admitted by all the naturalists already quoted, that the nest in question is built on moist ground, if not actually touching the water, and that part at least of the materials consist of moist water-plants. Now, it is indispensable to hatching, that the eggs be kept at a high temperature, and not be suffered for a moment to cool. The natural heat of the bird itself is sufficient for this purpose, without the heat of fermentation, erroneously supposed by Pennant; but if she quits them for a moment to go in pursuit of food, or to withdraw the attention of an intruding water-spaniel, or a prying naturalist, their near vicinity to moist plants or to water, would certainly prove fatal to the embryo chicks. In order then to prevent her brood from being destroyed by cold, the careful bird covers the eggs with a quantity of dry hay, to keep them warm till her

return.

"By keeping this interesting fact in his mind, our young naturalist may subsequently find that other birds employ the same, or similar devices. The carrion-crow, (Corvus corone,) for example, who lines her nest with wool and rabbits' fur, always covers her eggs with a quantity of this before leaving her nest, no doubt, for the same reason that the dabchick employs hay. Again, several birds of very different habits, such as the wood-wren, (Sylvia sibilatrix,) and the hay-bird, (Sylvia trochilus,) construct a permanent arch of moss and dried grass over their nests, leaving a narrow entrance in the side. Having recently had occa

sion to investigate the structure of various nests with some minuteness, I have been led to adopt the opinion, that the arched coping, or dome, so remarkable in several small birds for ingenious and beautiful workmanship, is designed to preserve their animal heat from being dissipated during the process of incubation; an opinion which appears to be corroborated by the fact of our native birds that thus cover in their nests at the top, being all very small.

"Among these, besides the wood-wren and the haybird, are the common wren, the chiff-chaff, (Sylvia hipolais,) the gold-crested wren, the bottle-tit, (Parus caudatus, RAY,) and the dipper, (Cinclus aquaticus, BECHSTEIN.) There are other birds, no doubt, little larger than these, such as the blackcap and the babillard, (Curruca garrula, BRISSON,) which do not build domed nests; but it is worthy of remark, that the latter usually lay much fewer eggs; the babillard seldom more than four, and the blackcap four or five; while the gold-crested wren lays from seven to ten, the bottle-tit from nine to twelve, and the common wren from eight to (some say) fourteen, and even twenty. It will follow of course, that in order to hatch so large a number, these little birds require all their animal heat to be concentrated and preserved from being dissipated. The dipper, indeed, lays but five or six eggs, and weighs from six to eight times more than any of our other dome builders; but it is to be recollected, that, from its being a water bird, and building near water, it may have more occasion to use 'all appliances' to concentrate its heat. In tropical countries, where the heat is great, such domed nests are very common, and are probably intended to protect the mother birds, while hatching, from the intense heat of a perpendicular sun; though most naturalists think they are designed to avert the intrusion of snakes,-forgetting that snakes would more naturally run their heads into a nest with a small side entrance, than if it were open above. A circumstance which fell under my observation, corrobative of this remark, I have recorded under the article Hay Bird. Other birds, in warm countries, leave their eggs during the day exposed to the heat of the sun, and only sit upon them during the night, or in cloudy weather, when the temperature of the air is not

sufficiently high, a fact which has given origin to the error, that the ostrich (Struthio camelus,) lays her eggs in the sand and abandons them to chance."

What, then, in the opinion of this acute observer and inquirer, is the use of what in natural history is called a system? A methodical classification is useful in as far only as it may serve as a framework or a cabinet, into the partitions of which many little facts may be stored and dove-tailed, that would otherwise be scattered through the memory at random, at the great hazard of being lost. The advantage of a system of this kind, then, consists in its preserving such collections of facts, as a cabinet preserves a collection of specimens; and, provided the several facts be not too far separated from their usual associations, it matters little what other qualities the systems possess. Simplicity, indeed, must always be valuable, and a simple system may be likened to a plain unornamented cabinet, where the specimens hold a prominent place, and the cabinet itself is almost overlooked; while a complex system may, in the same way, be likened to a cabinet bedizined with grotesque carving and fretwork, the compartments of which are curiously cut," and fantastically arranged, consisting indeed chiefly of empty framework, without a useful fact, or an interesting specimen on which the mind can rest; and afterwards Mr. Rennie says, with equal truth and boldness, of these same system-mongers, that the alphabet of their system is all they study, yet they scruple not to call themselves naturalists, and the alphabet of their system, Natural History, though they might, with equal propriety, call the twenty-four letters in a hornbook the History of England, and rank the village schoolmaster who teaches it with Hume or Lingard. That some minds may be so constituted as to take pleasure in such nick-nack study, is proved by the analogous pursuits of collectors of old coins and medals, not for their utility, but solely on account of their rarity, or to perfect a series; yet it would be as preposterous to rank such mere collectors with a man like Niebuhr, who investigated medallion inscriptions, in order to elucidate the history of Rome, as it would be to rank a mere systematist with Aristotle, Ray, or John Hunter.

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