Page:An introduction to physiological and systematical botany (1st edition).djvu/491

 Rh spur is present, the only nectary. Nor is this opinion so ill-founded as many botanists suppose; for the front of the lip evidently secretes honey in Ophrys (or Epipactis) ovata, t. 1548, and probably in others not yet attended to. Nevertheless, this lip might, like the petals of lilies, be deemed a nectariferous corolla, were it certain that all the other leaves were truly a calyx. But the 2 inner are so remarkably different from the 3 outer ones in Ophrys, t. 64, 65, 71, 383, and above all, in Stelis, ''Exot. Bot. t.'' 75, that I am most inclined to take the former for the corolla, the latter being, according to all appearance, a calyx. An insensible gradation from one to the other, of which we have pointed out other instances in treating of this subject already, occurs in Diuris, t. 8, 9; while in some Orchideæ the leaves all partake more of the habit of a calyx, and in others of a corolla. Even the lip in Thelymitra, t. 29, assumes the exact form, colour, and texture, of the rest of the flower; which proves that a dissimilarity between any of these parts is not always to