Though the wax of honey and brood-comb be an original secretion from the body of the bee, wax is also considered by some as a vegetable substance existing abundantly in nature. According to +Proust+, it forms the silvery down on the leaves, flowers and fruit of many plants, and resides likewise in the feculæ of others. +Dr. Darwin+, in his _Phytologia_, supposes that wax is secreted to glaze over the fecundating dust of the anthers, and prevent its premature explosion from excessive moisture: to an unseasonable dispersion of anther-dust he ascribes the failure of orchard and corn crops in summers of extreme humidity. The wax-tree of Louisiana[AC] (_Myrica cerifera_) contains immense quantities of wax. In this respect there appears an identity betwixt animal and vegetable secretion, which may be viewed as indicative of simplicity in the structure of the bee: a still simpler organization exists in the aphis, which extracts the saccharine juices from the leaves and bark of trees, and expels them again nearly unchanged[AD]. [Footnote AC: _Vide_ Part I. Chap. 28.] [Footnote AD: _Vide_ Part I. Chap. 5.] CHAPTER XXXVI. POLLEN. +_Pollen_+ and _Farina_, in the language of Botanists, are terms applied to the powdery particles discharged by the anthers of flowers in warm dry weather, and which hang about the stamina. The colour, as well as the structure of pollen, varies in different plants. Its use, in fecundating the germens of flowers, is well known: the services of bees, towards that end, will be noticed in a separate chapter. The sixth volume of the Linnæan Transactions contains an interesting paper upon this substance, from the pen of +Mr. Luke Howard+. _Pollen has a capsular structure_, varying its shape in different flowers, insomuch as to be a popular object for the microscope. Each grain consists commonly of a membranous bag, which, when it has come to maturity, bursts on the application of moisture: this bursting is naturally effected by the honey-like exudation of the stigma; but if extraneous moisture accomplish it prematurely, the pollen is rendered useless for the purpose of fructification. Whenever moistened, the bag explodes with great force, and discharges a subtle vapour or essence, which, when released by the peculiar moisture of the stigma, performs effectually its final purpose.