When a bee has completed her loading, she returns to the hive, _part_ of her cargo _is instantly devoured_ by the nursing-bees, to be regurgitated for the use of the larvæ, and _another part is stored_ in cells for future exigencies, _in the following manner_. The bee, while seeking a fit cell for her freight, makes a noise with her wings, as if to summon her fellow-citizens round her; she then fixes her two middle and her two hind legs upon the edge of the cell which she has selected, and curving her body, seizes the farina with her fore legs, and makes it drop into the cell: thus freed from her burthen, she hurries off to collect again. Another bee immediately packs the pollen, and kneads and works it down into the bottom of the cell, probably mixing a little honey with it, judging from the moist state in which she leaves it; an air-tight coating of varnish finishes this storing of pollen. From the uniform colour of each collection, it is reasonable to suppose that _the bee never visits more than one species of flower on the same journey;_ this was the opinion of +Aristotle+, and the generality of modern observers have confirmed it. +Reaumur+, however, supposed that the bee ranged from flowers of one species to those of another indiscriminately. +Mr. Arthur Dobbs+, in the Philosophical Transactions for 1752, states that he has repeatedly followed bees when collecting pollen; and that whatever flowers they first alighted upon decided their choice for that excursion, all other species being passed over unregarded: +Butler+ had previously asserted the same thing. Here we see the operation of a discriminating instinct, which in the first place leads the insect to make an aggregation of homogeneous particles, which of course form the closest cohesion; and in the next place prevents the multiplication of hybrid plants. This remark was made by +Sprengel+, who has confirmed the observations of Dobbs, Butler, and others. The bees, which Reaumur observed to visit flowers of different species, might have been in quest of honey as well as of pollen. CHAPTER XXXVII. PROPOLIS. Besides the honey and pollen which are gathered by bees, they collect a resinous substance, that is very tenacious, semitransparent, and which gives out a balsamic odour, somewhat resembling that of storax. In the mass, it is of a reddish brown colour; when broken, its colour approaches that of wax. Dissolved in spirit of wine or oil of turpentine, it imparts, as varnish, a golden colour to silver, tin, and other white polished metals. Being supposed to possess medicinal virtue, it was formerly kept in the shop of the apothecary. According to Vauquelin, propolis consists of one part of wax and four of pure resin; in which respect, and in its yielding the same acid, (the _benzoic_,) it resembles balsam Peru. It also contains some aromatic principles.