226 OTfPEIEEDEiE. CHAP. \lll. 



CHAPTEE Vin. 



CYPEIPEDE^ — HOMOLOGIES OF THE FLOWERS OF 

 OKCHIDS. 



Cypripedium, diffeia much ftom all other Orchids — Lahellum in the 

 form of a slipper with two small orifices by which insects can escape 

 — Manner of fertilisation by small bees of the genns Andrena — 

 Homological nature of the several parts of the flowers of the Orohidese 

 — ^Wonderful amount of modification which they have undergone. 



We have now armed at Lindley's last and seventh 

 tribe, including, according to most botanists, only a 

 single genus, Cypripedium, which differs fi'om all 

 other Orchids far more than any other two of these 

 do from one another. An enormous amount of ex- 

 tinction must have swept away a multitude of inter- 

 mediate forms, and has left this single genus, now 

 widely distributed, as a record of a former and more 

 simple state of the great Orchidean Order. Cypripe- 

 dium possesses no rostellum ; for all three stigmas 

 are fully developed, though confluent. The single 

 anther, which is present in all other Orchids, is here 

 rudimentary, and is represented by a singular shield- 

 like projecting body, deeply notched or hollowed out 

 on its lower margin. There are two fertile anthers 

 which belong to an inner whorl, represented in ordinary 

 Orchids by various rudiments. The grains of poUen 

 are not united together by threes or fours, as in so 

 many other genera, nor are they tied together by 

 elastic threads, nor furnished with a caudicle, nor 

 cemented into waxy masses. The labellum is of 



