688 Mr. Brown on the Organs and Mode of 
pregnating many species belonging to different tribes of Orchi- 
dez, by applying the pollen masses to the stigma, whose channel 
communicating with the cavity of the ovarium, and first noticed 
by Haller, he also describes. 
In 1827, Professor L. C. Treviranus* published an account 
of several experiments made by him in 1824, which satisfacto- 
rily prove that impregnation in this family may be effected by 
the direct application of the pollen to the stigma. 
About the end of 1830 a letter from Professor Amicit to 
M. Mirbel was published, in which that distinguished micro- 
scopical observer asserts that in many phenogamous plants the 
pollen tubes, or boyaux, penetrate through the style into the 
cavity of the ovarium, and are applied directly to the ovula. 
In this important communication Orchidee are not men- 
tioned, but M. Adolphe Brongniart in a note states that he 
himself has seen the production of boyaux or pollen tubes even 
in this family ; that here, however, as well as in all the other 
tribes in which he had examined these tubes, he found them 
to terminate in the tissue of the stigma. 
Of the second class of authors the earliest is Linnzeusi, who, 
in 1764, not satisfied either with his own or any other descrip- 
tion then given of the stigma, inquires whether the influence 
of the pollen may not be communicated internally to the 
ovarium. | 
In 1770, Schmidel$, in an account which he gives of a spe- 
cies of Epipactis, describes and figures the upper lip of the 
stigma, the rostellum of Richard, with its gland both before and 
after the bursting of the anthera; and as he denominates that 
* Zeitschrift f. Physiol. ii. p. 225. + Annal. des Sc. Nat. xxi. p. 329. 
t Prelect. in Ord. Nat. ed. Giseke. p. 182. 
S Gesn. Op. Bot, hist. plant. fasc. ii. p. 15. tab. 19. 
. part, 
