Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/127

. IV. cement is dry the attachment is wonderfully strong. The transparent sides of the rostellum consist of membrane, attached behind to the edges of the boat, and folded over in front, so as to form the anterior face of the rostellum. This folded membrane, therefore, covers, almost like a deck, the cargo of viscid matter within the boat.

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The anterior face of the rostellum is slightly furrowed in a longitudinal line over the middle of the boat, and