THE ORCHID REVIEW. 295 
NOTES ON THE FERTILISATION OF ORCHIDS 
IN THE TROPICS. 
NUMEROUS observations respecting the fertilisation of Orchids, both in a 
wild and cultivated state, have been recorded, and the following notes from 
Costa Rica may therefore be of some interest :— 
The Orchids of my large collections, although cultivated in the open 
air, and therefore exposed to all possible insect and other agencies of fertili- 
sation, in most cases fail to produce seed pods, though in a few kinds they 
do it exceptionally, but always in a much less degree than in their true 
native homes. For example, Cattleya Dowiana in its native habitat pro- 
duces a seed pod almost out of every flower; here in San José—about 
fifty miles from its home—I had last April nearly four hundred plants in 
perfect flower, but although the air above them was humming with bees, 
they produced not one seed pod, except a few plants which I fertilised 
artificially with pollen of C. Mossiz. 
Bees play a very insignificant part in the fertilisation of Orchids here. 
I keep in my nurseries an apiary averaging a hundred hives of Italian bees, 
together with a few colonies of different kinds of native stingless bees. 
The hives are placed in long rows alongside an orchard of oranges and 
other fruit trees, giving different grades of shade to the large collections of 
native and foreign Orchids I am cultivating beneath them. Now although 
I am almost every day among the Orchids, and although daily perhaps a 
million bees are flying straight across the Orchid garden, yet during all 
these years I have seen scarcely a dozen bees alight on Orchid flowers, and 
among these few not one touched the pollen-masses, much less carrying 
them to the stigma. Yet I remember perfectly well that in European 
stoves it is no rare occurrence to see bees alighting on Orchid flowers. 
I myself have seen it several times, and although I at that time took little 
care to see if fertilisation really took place, I have little doubt that it did. 
Most Orchids seem to have each species its own fertilising insect, which 
must in most cases be of a very restricted local occurrence, and without 
which the respective Orchid, even under quite identical climatic conditions, 
may thrive and flower individually, but without propagating itself. And 
this explains at once the truly surprising local distribution of the majority 
of Orchids, and also the yet more surprising fact, that certain species are 
found in very far distant localities. Thus Oncidium Kramerianum at 
Guyaquil in Ecuador, and again in Port Limon in Costa Rica ; Cypripedium 
caudatum in Chiriqui, Colombia, and again in Peru, &c. 
That the above conclusions are not mere theories is sufficiently 
proved by the sterility of my cultivated Orchids, in proof of which I may 
state the following observations, out of a good many more which I could 
give :— 
