without injury to the fructification of the plants. So far, indeed, from being an obstacle to this, the bees, on the contrary, greatly facilitate it, by applying in their movements the fertilizing farina to the stigma of the flower.
Propolis.—Propolis is a tenacious substance, generally of a dull grey colour, gathered by the bees from the buds of certain trees in early spring; especially from the alder, the poplar, the birch, and the willow. It is of great use to the insect in various ways. The ancients supposed it to consist of three different substances, or rather, perhaps, three different modifications of the same substance, according to the different proportions of wax blended with it, and have been followed in this opinion by some more recent inquirers; yet the generality of intelligent Bee-masters are satisfied that it is in fact a single substance when collected by the bees, and that it is afterwards, when used, mixed by them with common wax in different proportions, according to the purpose for which it is employed. Huber, to ascertain the fact of its origin, stuck some branches of the wild poplar in pots of earth, in front of his apiary. The bees immediately discovered them, and set about loading themselves with the identical substance, which he had often detected adhering to their thighs in the same manner as farina. He observed them "separating the folds of the buds with their teeth, drawing out threads of the viscous substance, and lodging a pellet of it in one of the baskets of their limbs." He ascertained farther, that branches newly cut did not
