490 ON THE ORGANS AND MOJDE OF FECUNDATION 



ORCHIDEiE. 



The authors whose opmions or conjectures on the mode 

 of impregnation in Orchideee I have to notice, may be 

 divided into such as have considered the direct application 

 of the pollen to the stigma as necessary : and those who, — 

 from certain peculiarities in the structure and relative posi- 

 tion of the sexual organs in this family, — have regarded 

 the direct contact of these parts as in many cases difficult 

 686] or altogether improbable, and have consequently had 

 recourse to other explanations of the function. 



In 1760, Haller, the earhest writer.of the first class, in 

 describing his Epipactis, states that the antherse or pollen 

 masses, after leaving the cells in which they are originally 

 inclosed, are retained by the process called by him susten- 

 taculum, the rostellum of Richard, from which they readily 

 fall upon the stigma.^ He adds, that both in this genus 

 and in Orchis the stigma communicates by a fovea or 

 channel with the ovarium. 



But as in 1742 he correctly describes the stigma of 

 Orchis,^ and in his account of Epipactis^ notices also the 

 gland derived, as he says, from the sustentaculum, and 

 which is introduced between and connects the pollen masses, 

 his opinion on the subject, though not expressed, is dis- 

 tinctly implied even at that period ; or as indeed it may 

 be said to have been so early as 1736,* when he first de- 

 scribed the channel communicating with the ovarium, and 

 considered it as being in the place of a style. 



In 1763, Adanson^ states that the pollen masses are 

 projected on the stigma, of which his description is at 

 least as satisfactory as that of some very recent writers on 

 the subject. He also describes the flower of an Orchideous 

 plant as being monandrous, with a bilocular anthera, con- 

 taining pollen which coheres in masses (a view of structure 



' Orchid, class. comtiUit. in Act. Heloet. iv, p. 100. 

 ^ Hall. Enum. p. 262. 3 Jd. p. 274. 



Melh. stud. lot. p. 21. '' Fam. des Plant, ii, p. 09. 



