enotes the art of retrenching, or cutting away any part of a thing from its whole.—Castrating a book, among bookellers, is the taking out some leaf, sheet, or the like, which renders it imperfect and unfit for sale. The term is also applied to the taking away particular passages, on account of their obscenity, too great freedom with respect to government, &c.

Castration, among botanists, a term derived from the fancied analogy between plants and animals. The castration of plants consists in cutting off the antheræ, or tops of the stamens, before they have attained maturity, and dispersed the pollen or fine dust contained within their substance. This operation has been frequently practised by the moderns, with a view to establish or confute the doctrine of the sexes of plants; the antheræ or tops being considered by the sexualists as the male organs of generation. The experiment of castration succeeds principally on plants which, like the melon, have their male flowers detached from the female. In such as have both male and female flowers contained within the same covers, this operation cannot be easily performed without endangering the neighbouring organs. The result of experiments on this subject by Linnæus, Alston, and other eminent botanists, may be seen under the article Botany, sect. iii.