[7] "Naturalist's Library."
The insect is divided into three parts—the head, the thorax or chest, and the abdomen.
The head of the queen ([Plate I., fig. 1 c]), as also that of the drone ([Plate I., fig. 3 c]), is rounder than that of the worker-bee. The latter ([Plate I, fig. 2 c]) is of a triangular shape, and much flattened, as in [Plate I., fig. 2* c], which shows the side view. In common with other creatures, the head contains the inlet for nutrition, and is the seat of the principal organs of sensation.
In the figures before alluded to may be seen the double visual apparatus with which bees are provided. The oval divisions on each side of the head are the two eyes, the secondary organs of vision being the three small eyes on the top of the head, called the ocelli. We shall first describe the two larger eyes, which, as seems to be the case with all insects, are immovable, and have neither irides nor pupils, nor eyelids to cover them, but are protected from the dust or pollen of flowers by a number of small hairs, as well as by a horny tunicle, which defends and secures them from injury. The multitude of hexagonal lenses which compose the eye of a bee make it appear, when viewed through a microscope, exactly like honey-comb.[8] A German writer computes that in each eye there are 3,500 lenses. In [Plate II., fig. 5] represents three of these hexagonal prisms or lenses, magnified.
[8] Dr. Bevan.
The construction of the eye for seeing objects best at a moderate distance will account for the fact that bees mount high up into the air after collecting their store of food, and then, having determined the point, no matter how far off, they fly homewards with the directness of a cannon ball, and alight at the door of their own habitation, though the country around may be crowded with hives: but on reaching the entrance, their vision appears defective, for they then feel their way with the antennæ as if totally blind; and should the hive have been moved a little, they will rise again into the air to obtain a more distant view, suited to the lengthened focus of their sight.
When a stock or swarm is brought from a distance, bees do not take their departure at once, but reconnoitre awhile, visiting surrounding objects so as to well know the spot again, in order to return thereto.
The precise purpose or use of the three small eyes does not appear to be exactly known, except that they are intended to heighten the general sense of seeing which the creature so peculiarly requires. Some naturalists suggest that they are to give a defensive vision upwards from the cups of flowers.
The mouth of the bee is a most complex structure, marvellously adapted for its duties, and consists of the mandibles, the ligula, or tongue, also called the proboscis, and other less important parts. The mandibles are the two sides of the upper jaw. [Plate I., fig. 1 d], shows the mandible of the queen, which, similar to that of the drone ([Plate I., fig. 3 d]), is provided with two teeth, whilst the mandible of the worker ([Plate I., fig. 2 d]) is without teeth. The latter having to manipulate the wax with smoothness, the teeth would doubtless be objectionable. These mandibles are strong, horny, and sharp-pointed, to assist in breaking down food between them, and, in other respects, constitute serviceable tools with which to seize their enemies, destroy the drones, &c. The tongue ([Plate II., fig. 3]), or proboscis, is a long, slender projection, flattish in form, and about the thickness of a bristle. It has about forty cartilaginous rings, each of which is fringed with minute hairs, having also a small tuft of hair at its extremity, where it is somewhat serrated. The tongue acts by rolling about, sweeping or lapping up, by means of the fringes around it, everything to which it is applied; thus, when a bee alights upon a flower, it pierces the petals and stamina, where the nectar is secreted, deposits its collection on the tongue, which, when withdrawn into the mouth, propels the gathered material into the gullet ([Plate I., fig. 2 c]) at its base, and from thence passes into the various internal organs, to which reference will be made hereafter. At times, in building combs, the tongue is used as a trowel, with which the minute scales of wax are deposited in their appropriate places, and the desired finish is given to the cells. This organ was formerly described by naturalists as a hollow tube, but we now know, by dissection, that this is not the case, but that it acts as a brush, and, by a peculiar muscular contraction externally, draws the liquid into the mouth. Thus, when a bee is imbibing food, the rings of the abdomen have a vibratory motion similar to pumping, showing to the casual observer that suction is rapidly going on in some form or other.
The labial palpi ([Plate II., fig. 3 o]) rise from the base of each side of this lapping instrument, and are also ciliated exteriorly; outside these are the lower jaws, or maxillæ ([Plate II., fig. 2 n]), similarly provided with hairs. When the jaws ([Plate II., fig. 3 n and o]) close on the tongue, they form a sheath or defence thereto.