periment is the more important, as the abbé Spallanzani has recorded one made by himself upon the same species of plant, with a contrary result. But as he has said nothing of the appearance of the stigmas, his experiment must yield to that of Linnæus in point of accuracy; and even if his account be otherwise correct, the result is easily explained. Hemp, Spinach, some Nettles, &c., naturally diœcious, are occasionally not completely so, a few latent barren or fertile flowers being frequently found among those of the other sort, by which provision is made against accidents, and the perfecting of a few seeds, at any rate, secured.
In general, germens whose stigmas have not received the pollen wither away without swelling at all, but some grow to a considerable size, and in such the substance of the seed, its skin, and even its cotyledons, are often to be found, the embryo only being wanting. In a Melon or Cucumber it is common to find, among numerous perfect seeds, many mere unimpregnated husks. In the magnificent Cycas revoluta which bore fruit at the bishop of Winchester's, and of
