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50 presents a wonderful contrast in every flower producing a capsule.

Ophrys aranifera, or the Spider Ophrys.—I am indebted to Mr. Oxenden for some spikes of this rare species. Whilst the pollinia remain enclosed within their cells, the lower part of the caudicle projects up in a straight line from the viscid disc, and therefore has a very different form from the corresponding part of the caudicle of O. muscifera; but the upper part (A, fig. 6) is a little bent forward, that is, towards the labellum. The point of attachment of the caudicle to the disc is hidden within the bases of the anther-cells, and is thus kept damp; consequently, as soon as the pollinia are exposed to the air, the usual movement of depression takes place, and they sweep through an angle of about ninety degrees. By this movement they assume, supposing them to be attached to an insect's head, a position exactly adapted for striking the stigmatic surface, which is situated, relatively to the pouch-formed rostella, rather lower down in the flower than in the Fly Ophrys.

I examined fourteen flowers of the Spider Ophrys, several of which were partly withered; and in none were both pollinia, and in three alone was one pollinium removed. Hence this species, like the Fly Ophrys, is but little visited by insects in England. In parts of Italy it is even less visited, for Delpino states that in Liguria hardly one flower out of 3000 sets a