CONTENTS. Xm 



CHAPTEE VI. 



Structure of the column and poUinia — Importance of the elasticity 

 of the pedicel ; its power of movement — Elasticity and strength 

 of the caudicles — Calanthe with lateral stigmas, manner of 

 fertilisation — Angrajcum sesquipedale, wonderful length of nec- 

 tary — Species with the entrance into the st^matio chamber 

 much contracted, so that the pollen-masses can hardly be 

 inserted — Coryanthes, extraordinaiy manner of fertilisation 



Pages 149-177 



CHAPTEE VII. 



VANDE« continued. — catasetid^. 



Catasetidse, the most remarkable of all Orchids — Tlie mechanism 

 by which the pollinia of Catasetum are ejected to a distance and 

 are transported by Insects — Sensitiveness of the horns of the 

 rostellum — Extraordinary difference in the male, female, and 

 hermaphrodite forms of Catasetum tridentatiim — Mormodes 

 ignea, curious structure of the ilowers ; ejection of the pollinia 

 — Mormodes luxata — Cyonoches ventricosum, manner of fei-- 

 tilisation 178-225 



CHAPTEE VIII. 



CYPRIPEDE^ — HOMOLOGIES OF THE FLOW^EHS OF OBCHIDS. 



Cypripedium, differs much from all other Orchids — Labellum in 

 the form of a slipper with two small orifices by which insects 

 can escape — Manner of fertilisation by small bees of the genus 

 Andrena — Homological nature of the several parts of the flowers 

 of the Orchidese — Wonderful amount of modification which 

 they have undergone 226-246 



