If we observe this same peculiarity of structure in the cuckoo, or parasitical bees, it is because we find resemblances where there are alliances. Thus, the male artisan bees, although not assisting in the labour of constructing the apartments, have similarly dilated mandibles to those of their females. So also, in the form of the abdomen, the _Nomadæ_ are like the _Andrenæ_ and _Halicti_, upon which they are chiefly parasitical. _Melecta_ resembles _Anthophora_; _Cælioxys_ has the form of _Megachile_, both in the hollowed base of the abdomen and the peculiar manner the latter has of raising its extremity,—something like a _Staphylinus_. Many other peculiarities of resemblance might be enumerated. Having thus completed the description of the external anatomy of the bee desirable to be known for facilitating the comprehension of what I may have subsequently to say. I shall now refer to a few peculiarities of their manners, which could not be conveniently introduced elsewhere. In their modes of flight bees vary considerably; some dart along in a direct line, with almost the velocity of lightning, visit a flower for an instant, and then dart off again with the same fleetness and vivacity, like _Saropoda_ and _Anthophora_; others leisurely visit every blossom, even upon a crowded plant, with patient assiduity, like _Bombus_; and some, either from fatigue, or heat, or intoxication, repose, like luxurious Sybarites, within the corolla of the flower. The males seem to flutter about in idle vagrancy, and may be often observed enjoying themselves upon some fragrant hedge-row. But the domestic bee and the humble-bee are the most sedulous in their avocation, and both cheering their labour with their seemingly self-satisfied and monotonous hum. Bees, too, have a voice; but this voice does not proceed from their mouth, nor is it the result of air passed from the lungs through the larynx, and modulated by the tongue, teeth, and lips; for bees breathe through spiracles placed laterally along the several segments of the body, and their interior is aerified by tracheæ, which ramify variously through it; but their voice is produced by the vibration of the wings beating the air during flight. Even as Linnæus constructed a floral clock to indicate the succession of hours by the expansion of the blossoms of flowers, so might a Beethoven or a Mendelssohn—the latter in the spirit of his philosophical ancestor—note down the several sounds of the hum of the many kinds of bees to the construction of a scale of harmonic proportions, whose Æolian tones, heard in the fitfulness of accidental reverberation amidst the solitudes of nature, repeatedly awaken in the mind of the entomologist the soothing sensation of a soft, voluptuous, but melancholy languor, or exhilarate him with the pleasing feeling of brisk liveliness and impatient energy.