Fecundation in Orchidee and Asclepiadea. 701 
In most other cases the anterior lobe, or that placed opposite 
to the perfect stamen, and deriving its vessels from the same 
cord, manifestly differs both in form and texture from the other 
two. To this anterior, or upper lobe, as it generally becomes 
in the expanded flower, the glands always belong to which the 
pollen masses become attached, but from which they are in all 
cases originally distinct, as may be proved even in Ophrydez. 
According to my view, therefore, of the mode of impreg- 
nation, its office is essentially different from that of the two 
lateral lobes or stigmata, which in various degrees of develop- 
ment are always present, and in all cases, when the ovarium is 
perfect, are capable of performing their proper function. 
The greatest development of these lateral stigmata takes 
place in the tribe of Satyrinze or Ophrydez, as in many species 
of Habenaria, those especially which are found near or within 
the tropics; and still more remarkably in Bonatea speciosa, a 
plant hardly indeed distinguishable from the same extensive 
genus. 
It would seem that in Bonatea the extraordinary development 
and complete separation ‘of these lateral stigmata, have effec- 
tually concealed their true nature; and accordingly they have 
uniformly been considered as forming parts or appendages of 
the labellum, with which indeed their bases cohere. ‘That they 
are really stigmata, however, I have proved by a careful exa- 
mination of the tissue of their secreting surface, by the action 
of the pollen artificially applied to this tissue, by the descent 
of its tubes, hereafter to be described, along the upper sur- 
face of the styles which is destitute of epidermis, and -by 
the consequent enlargement of the ovarium.  Diplomeris of 
Mr. Don*, which may also be regarded as a species of Ha- 
benaria, is another example of nearly the same kind; and the 
* Prodr. Flor. Nepal. p. 26. 
description 
