Page:An introduction to physiological and systematical botany (1st edition).djvu/329

 Rh in Gærtner, t. 66, each having a double skin and no more, which is one covering less than even the genuine nut of the stone fruit, or of the Corylus. In Geranium, Malva, &c., what has often been called Arillus, is rather a kind of Capsule, not only because their seeds have a double or even triple skin, quite unconnected with this outer cover, but because the latter is analogous to other Capsules.

The loose husky covering of the seed in Carex is surely an Arillus. See ''Engl. Bot. also the Rev. Mr. Wood's observations on this genus in Dr. Rees's Cyclopædia, and Gærtner, v.'' 1. 13. This seed has besides a double Testa, though most of the true Grasses have but one, which in ground Corn constitutes the bran, the husks of the blossom being the chaff.

Pappus, the Seed-down, is restrained by Gærtner to the chaffy, feathery, or bristly crown of many seeds that have no Pericarpium, and which originates from a partial calyx crowning the summit of each of those seeds, and remaining after the