CONTENTS. XIU 



CHAPTER VI. 



VAXDE^. 



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 oi 

 fertilisation — Angrsecum sesquipedale, wonderful length of nec- 

 tary — Species with the entrance into the stigmatic chamber 

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

 inserted — Coryanthes, extraordinary manner of fertilisation 



Pages 149-177 



CHAPTEE YII. 



VANDEiE continued. — catasetid^. 



Catasetidaj, the most remarkable of all Orchids — The mechauisir 

 by which the poUinia of Catasetum are ejected to a distance ana 

 are transported by insects — Sensitiveness of the horns of the 

 rostellum — Extraordinary difference in the male, female, and 

 hermaphrodite forms of Catasetum tridentatum — Mormodes 

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

 — Mormodes luxata — Cycnoches ventricosum, manner of fer- 

 tilisation 178-225 



CHAPTER VIII. 



CYPKIPEDE^ — HOMOLOGIES OF THE FLOWERS OF OECHIDS. 



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 Orchideje — Wonderful amount of modification which 

 ihey have undergone 226-246 



