Fecundation in Orchidee and Asclepiadee. 715 
nally a granular appearance, which has been noticed though its 
cause seems to have been overlooked. 
In the recent work of Meyen *, also, some examples of these 
crystals in Orchidee are given. 
ASCLEPIADE. 
The various statements and conjectures on the structure and 
functions of the sexual organs in this family were collected, 
and published in 1811, by the late Baron Jacquin, in a se- 
parate volume, entitled, ** Genitalia Asclepiadearum Contro- 
versa." 
To this work, up to the period when it appeared, I may refer 
for a complete history, and to the tenth volume of the Linnean 
Society's Transactions, along with the first of the Wernerian 
Natural History Society's Memoirs, published somewhat earlier, 
for a slight sketch, of the subject. 
I shall here therefore only notice such statements as Jacquin 
has either omitted or imperfectly given, and continue the history 
to the present time. _ 
In 1763, Adanson correctly describes the stamina in Asclepias 
as having their filaments united into a tube surrounding the 
ovaria, their anthere bilocular and cohering with the base of 
the stigma, and the pollen of each cell forming a mass composed 
of confluent grains as in Orchidez. He is also correct in con- 
sidering the pentagonal body as the stigma; but he has entirely 
overlooked its glands and processes, nor does he say anything 
respecting the manner in which the pollen masses act upon or 
communicate their fecundating matter to it. — 
In 1779, Gleichen t, although he expressly says that in young 
flower buds the pollen masses are distinct from those glands of 
the pentagonal central body to which they afterwards are at- 
* Phytotomie. + Microscop. Entd. p. 73, et seq. ked 
tached, 
