Chap. IV. 



SPIRANTHES AUTUMNALIS. 



107 



cement is dry the attachment is wonderfully strong. 

 The transparent sides of the rostellum consist of mem- 

 brane, attached behind to the edges of the boat, and 

 folded oyer 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. 



Fig. 17. 



SPIRA^fTlIES AUTUMSAI.KS, Oil LaDIES'-TeESSES. 



a. anther. 



p. poUen-massos. 



t. threads of the pollen-masses. 



c^. margin of cllnandrum. 



r. rostellum. 



s. stigma. 



n. nectar receptacle. 



A. .Side view of flower in its natural 

 position, with the two lower 

 sepals alone removed. The 

 labellum can be recognised by 

 its fringed and reflexed lip. 



&. Side view enlarged of a mature 

 flower, with all the sepals and 

 petals removed. The positions 

 of the labellum and of the 



upper sepal are shown by the 

 dotted lines. 



C. Front view of the stigma, and 



of the rostellum with its em- 

 bedded, central, boat-formed 

 disc. 



D. Front view of the stigma and of 



the rostellum after the disc has 

 been removed. 



E. Disc, removed from the rostel- 



lum, greatly enlarged, viewed 

 posteriorly, with the attached 

 elastic threads of the pollen- 

 masses ; the pollen-grains have 

 been removed from the threads. 



The anterior face of the rostellum is slightly furrowed 

 in a longitudinal line over the middle of the boat, and 



