hair, to enable them to sweep off and collect the pollen, and to assist also in the construction and furnishing of their burrows. The intermediate tarsi are as well often very much extended in the males, being considerably longer than those of the other legs. The use of the claws at the apex of the tarsi is evidently to enable the insect to cling to surfaces. The manner in which the bee conveys either the pollen, or other material it purposes carrying home, to the posterior legs, or venter, which is to bear it, is very curious. The rapidity of the motions of its legs is then very great; so great, indeed, as to make it very difficult to follow them; but it seems first to collect its material gradually with its mandibles, from which the anterior tarsi gather it, and that on each side passes successively the grains of which it consists to the intermediate legs by multiplicated scrapings and twistings of the limbs; this then passes it on by similar manœuvres, and deposits it, according to the nature of the bee, upon the posterior _tibiæ_ and _plantæ_, or upon the _venter_. The evidence of this process is speedily manifested by the posterior legs gradually exhibiting an increasing pellet of pollen. Thus, for this purpose, all the legs of the bees are more or less covered with hair. It is the mandibles which are chiefly used in their boring or excavating operations, applying their hands, or anterior tarsi, only to clear their way; but by the constructive or artisan bees they are used both in their building and mining operations, and are worked like trowels to collect moist clay, and to apply it to the masonry of their habitations.