DR. H. CRUGER ON THE FECUNDATION OF ORCHIDS. 127 
A few Notes on the Fecundation of Orchids and their Morphology. 
By Dr. H. Crüger, Director of the, Botanical Garden, Trinidad. 
Communicated by CHARLES Dan, Esq., F.R.S. 
[Read March 3, 1864.] 
[Prats IX.] 
Whoever has read C. Darwin’s remarkable work on the fecun- 
dation of Orchids must have regretted that the chapters on 
tropical and other foreign Orchids leave a certain amount of un- 
certainty on the mind of the reader until the observations and 
suppositions shall have been endorsed by actual facts observed in 
the native countries of these plants. To fill up, as far as lies in 
my power, this blank is the purpose of the following observations 
and notes, to which I have added some remarks which I hope will 
not be deemed out of place. _ 
Of the larger-flowered Catasetidee we have here in Trinidad 
three genera (defining the section somewhat differently from 
Dr. Lindley). These are Catasetum, Coryanthes, and Stanhopea. 
Of the first we have one species, C. tridentatum, very common, 
and in various varieties, of which some authors have thought 
proper to make species. It shows in this island both the extreme 
forms, which I do not hesitate to call male and female; very 
frequently intermediate forms may be seen. I may state at once 
that these latter are always sterile. The two principal forms 
have been described so often, and latterly so well by Darwin, that 
I may restriet myself to a very few words, bearing principally on 
the essential parts for fecundation. 
The anther and pollen of the male flower are principally dis- 
tinguished by size and quantity from the corresponding parts in 
the female flower ; the microscopic character of the pollen-tetrades 
is the same in both. We shall see further on that it is not so with 
their physiological action. The anther of the female flower drops 
off immediately after the opening of the same, i. e. before the 
flower has reached perfection as regards colour, size, and smell. 
The disk (of Darwin ; eaudicle of other authors) does not cohere, 
or very slightly, to the pollen-masses, but drops off about the same 
time, with the anther. In the male flower, where the pollen- 
masses, &c., are in a much more considerable state of development, 
the deficiency is in the conducting tissue (tela conduetrix), which 
is the true stigma of this and allied plants as far as function is 
concerned. While in the male flower there is only a thin layer of 
this tissue lining the stigmatie canal, it is very abundant in the 
LINN. PROC.—BOTANY, VOL. VIII, M 
