Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/501

Rh circumstances, either into a worker or a queen. It has been proved that the former, although exhibiting no appear ance of sexual organs on a superficial examination, are in reality females, and have the rudiments of these organs, which, however, not being developed, are incapable of exercising their proper functions, although it sometimes happens that they become sufficiently so to enable a worker to lay unfecundated eggs. It may be remarked that the idea of the worker bees being radically females had been suggested long ago by Dr Warder in his Monarchy of Bees, in which he terms them &quot; True Amazons ; &quot; but no atten tion had been paid to his opinion. The real merit of this great discovery, which affords a key to a multitude of hitherto inexplicable facts, unquestionably belongs to Schirach. When first announced to the world it was received with suspicion by the greater number of natura lists, and with complete incredulity by others. It was, indeed, at variance with the whole tenor of the observations of Swammerdam, Maraldi, and Keaumur. Wilhelmi, the brother-in-law of Schirach, though an eye-witness of the experiments from which this theory had been deduced; for a long time refused to admit the doctrine, but at length became one of its most strenuous supporters. It is noticed in a vein of sarcastic ridicule by John Hunter in his otherwise excellent paper on bees in the Philosophical Transactions. Needham wrote a Memoir for the Imperial Academy of Brussels in 1777 for the express purpose of refuting it, and he then inveighs in strong language against those naturalists who had deigned to give it the least countenance. Bonnet, after exercising a laudable scep ticism, and making a diligent inquiry, in which he displays a genuine spirit of philosophy, yielded a reluctant assent. But the truth of the doctrine has since been placed beyond the reach of controversy by a multiplied series of obser vations and experiments in different parts of Europe and America.

In considering the physiology of the bee, the first function that claims our notice is that of nutrition. The food of bees is principally of two kinds, namely, the fluid secretions of vegetables contained in the nectaries of the flowers, and the dust of the anthers, which has been termed by botanists the pollen, but which, when collected by the bees, has received a variety of appellations, such as farina, bee-bread, &c. Occasionally, however, we find bees feeding upon other saccharine substances besides honey, such as honey-dew, syrup, &c.

The organs by which they collect food are extremely complex, comprising instruments adapted to the reception of liquid aliment as well as those fitted for the division of solid materials. Reaumur has given a most elaborate description of these organs, and corrects some errors into which Swammerdam had fallen. For the purpose of taking up fluids, bees are provided, in common with all hymen- opterous insects, with a long and flexible proboscis or trunk, which may be considered as a lengthened tongue, though, strictly speaking, it is formed by a prolongation of the under lip. It is not tubular, as Swammerdam had supposed, but solid throughout; and the minute depression at its extremity is not the aperture of any canal through which liquids can be absorbed. The trunk of the bee per forms strictly the office of a tongue, and not that of a tube for suction ; for when it takes up honey or any other fluid aliment, the under or the upper surfaces are more imme diately applied to it, and rolled from side to side, and the bee thus licks up what adheres to it, while the extremity of the trunk is frequently not applied at all to the substance taken up. The trunk is supported on a pedicle, which admits of being bent back or propelled forwards, and thus can retract or stretch out the trunk to a considerable extent. Protection is given to it by a double sheath ; the exter nal part consisting of two scales furnished by the expansion of one of the portions of the labial palpi, and the internal formed by the prolongation of the two external portions of the jaw. The whole member thus consists of five principal parts, on which account .Fabricius termed it lingua qidnqiiefida.

For the purpose of mechanically dividing solid materials, the mouth is furnished with two strong mandibles and four palpi ; they are but little employed in eating, but are of great use in enabling the insect to seize and break down hard substances for other purposes. In the worker bee all these parts are of larger dimensions than in the other kinds. The teeth are two in number, and have the form of concave scales with sharp edges ; they are fixed to the ends of the jaws, and play horizontally as in other insects. B,eaumur describes and delineates a large aperture above the root of the proboscis, which is so surrounded with fleshy parts as not to be readily seen unless the proboscis be extended and bent downwards. This he considers as the mouth or orifice of the gullet ; on the upper side of which, and of course opposite to the root of the proboscis, a small fleshy and pointed organ is seen, which he regards as the tongue, assisting in the deglutition of the food. Through this orifice, it is presumed, all the aliment, whether liquid or solid, passes ; the former being conveyed to it by the trunk, which, by its contractile power, presses forward the fluids it has collected between itself and the inner sheath, and the latter being received directly after its comminution by the teeth, behind which it is situated. Latreille, howeve^ whose authority is great on a point of this nature, thinks that Reaumur has deceived himself with regard to such an aperture, and disbelieves its existence. He con ceives that the food simply passes on by the sides of the tongue, finding its way from thence into the oesophagus and so on to the stomach.

The bee has two stomachs. The first is a large transparent membranous bag, pointed in front and swelling out into two pouches behind. It performs an office hi some respects analogous to that of the crop in birds ; for it receives and retains for a time the fluid of the nectaries, which does not appear to differ in any respect from honey. Hunter observes that whatever time the contents of this reservoir may be retained he never found them altered so as to give the idea of digestion having taken place. The coats of this reservoir are muscular, by which means it is capable of throwing up the honey into the mouth, so that it is regurgitated into the honey cells or imparted to other bees. None of it ever passes out from the extremity of the trunk as Swammerdam had believed. For the purpose of diges tion a second stomach is provided, which takes its origin from the middle of the two posterior lobes of the former, and is of a lengthened cylindrical shape. Its communica tion with the intestine is not direct, but takes place by a projecting or inverted pylorus, thickest at its most prominent part, with a very small opening in the centre, of a peculiar construction. This inward projecting part is easily seen through the coats of the reservoir, especially if full of honey. A similar kind of structure takes place at the communica tion of the first with the second stomach, and having the properties of a valve, must effectually prevent all regurgita- tion from the latter into the former.

The pollen, or fertilising dust of flowers, is collected by the bees for the purpose of feeding the young. It is stored in the cells until required, and then partly digested by the nurses with honey, and a kind of chyle formed of it. When natural pollen cannot be obtained the bees will eagerly take farina, either of rye, chestnuts, or pease, as a substitute, which appears to answer the same purpose. The bees, by means of the pencil of hair which grows on the tarsi, first collect a certain quantity of pollen, and then 