THE ORCHID REVIEW. 143 
hybrids as varieties of the species they most nearly resemble; a plan, as 
they well remark, ‘‘ by no means free from objection.” 
For several years I have made a study of these intermediate and 
doubtful forms, whenever the opportunity presented itself, and as numerous 
inquiries are continually being made on the subject, it seems desirable to 
place the results of my observations on record. 
In 1874, when Odontoglossum x Andersonianum first appeared, com- 
paratively little was known about hybrid Orchids, as the number of artificial 
ones which had reached the flowering stage could almost be counted on 
the fingers of both hands, as has been recently pointed out in these pages. 
At the* present time, however, not only has our knowledge of the subject 
generally been enormously increased, but the origin of two supposed 
natural hybrid Odontoglossums has been demonstrated by actual experi- 
ment, and the subject may therefore be said to have passed beyond the 
stage of mere speculation. 
From an attentive observation of the numerous Odontoglossums in 
cultivation, I have arrived at the conclusion that, in the majority of cases, 
it is possible to separate hybrid forms from genuine species and their 
Varieties, and that where this is not the case it is only because of the 
imperfect data at hand. It is fortunate that such is the case, for it is 
the first real step to the solution of the problem. It is not an easy matter 
to lay down any absolute rules on the subject, but the two groups are so 
*ssentially distinct in their origin that a very few considerations will serve 
to make the matter clear. 
A species, of whatever kind, has always a definite geographical area. 
over which the individuals which compose it are distributed, more or less 
continuously or disconnectedly according to circumstances. Taking this 
‘rea as a whole, the individuals are generally very numerous, and every- 
where they bear so strong a resemblance to each other that they can 
s‘nerally be recognised as belonging to the same species. Moreover the 
Mesent distribution, however wide, must be ascribed to gradual diffusion 
m some original birthplace. Orchids, generally speaking, are rather 
local in their distribution; but there are exceptions, and it has been 
"epeatedly observed that widely diffused species are the most variable. 
Sc noteworthy fact is that the most closely allied plants are usually 
M different localities. The explanation is very simple. 
nN a species becomes widely diffused, it almost invariably comes 
the influence of changed conditions, and as every part of an organism 
osely related to its complex conditions of life, a corresponding change 
plant necessarily takes place. Hence variations arise, which in 
“come more marked, and are called geographical varieties, and 
eri Subspecies, and species. An extension of ie process, together 
the €xtinction of intermediate forms, results in the formation of 
is ¢] 
in 
