Fecundation in Orchidece and Asclepiadea. 691 



column a glutinous disk, from which a central thread or cord of 

 the same nature is continued through the style to the cavity of 

 the ovarium, where it divides into three branches, and that 

 each of these is again subdivided into two. The six branches 

 thus formed, are closely applied to the parietes of the ovarium, 

 run down one on each side of the corresponding placenta to its 

 base, each giving off numerous ramuli, which spread themselves 

 among the ovula, and separate them into irregular groups. 



Hence, according to this author, a communication is esta- 

 blished between the anthera and the ovula, which he adds are 

 impregnated through their surface, and not, as he supposes to 

 be the case in other families, through their funiculus or point 

 of attachment to the placenta. 



The remarkable account of the stigma here quoted, though 

 coming from so distinguished and original an observer, and one 

 who had particularly studied this family of plants, seems either 

 to have been entirely overlooked, or in some degree discredited 

 by more recent writers, none of whom, as far as I can find, have 

 even alluded to it. And I confess it entirely escaped me until 

 after I had made the observations which will be stated in the 

 present essay, and which confirm its accuracy as to the exist- 

 ence and course of the parietal cords, though not as to their 

 nature and origin. 



In 1824 Professor Link* expresses his opinion that the rostel- 

 lum of Richard is without doubt the true stigma. 



In 1829 Mr. Lindleyt, who for several years has particularly 

 studied and has lately published part of a valuable systematic 

 work on Orchideous Plants, states that in this family impregna- 

 tion takes effect by absorption from the pollen masses through 

 their gland into the stigmatic channel. 



In 1830, in his Introduction to the Natural System of Botany. 



* Fhilos. Dot. p. 298. f Synops. Brit. Flor. p. 256. 



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