has only one covering, it is not always easy to say whether that be a Calyx or Corolla. When green and coarse in texture like the former, we call it so, as in Chenopodium, Engl. Bot. t. 1033, and 1721—4, and the natural relationship of this genus to Polygonum, t. 1044, 989, 756, &c., leads us to reckon the same part in the latter a coloured calyx. On the other hand, when the part present is delicate and finely coloured, like the generality of Corollas, we denominate it such; more especially if the plant to which it belongs be allied to others that have a Calyx besides, as in Tulipa, t. 63, allied to Leucojum, t. 621, which has a Spatha. The great Jussieu denominates this part in the Tulip and other liliaceous plants, however beautiful, a Calyx. His definition of a Corolla is "that covering of a flower which is invested with the calyx, being very rarely naked; a continuation of the inner bark of the flower-stalk, not of its cuticle; not permanent, but mostly falling off with the stamens; surrounding or crowning the fruit, but never growing united with it; and having its parts of segments for the most part alter-
