BIGENERIC ORCHID HYBRIDS. 165 
try to harmonize these two views, we are reduced to the neces- 
sity of merging the whole range of genera from Epidendrum to 
Bletia into one. 
Colax and Zygopetalum (the former reduced by Bentham to 
Lycaste, but here restored) belong to the subtribe Cyrtopodiee ; 
butas considerable differences exist in the structure of the polli- 
narium, they are placed twelve genera apart. In fact, Bentham 
makes two groups, one with an elongated stipes on which the 
pollen-masses are seated, the other having them sessile on the 
gland ; Colaz is placed in the former group, and Zygopetalum in 
the latter. So here, again, structural differences preclude the 
idea of merging the two genera in one. And if this were done, 
new characters must be sought for subdividing the Cyrtopodiea, 
or the nineteen genera be reduced to very few. 
The case of Phaius and Calanthe is yet more remarkable, as 
they are placed in distinct subtribes by Bentham—Phaius in 
Bletidee, and Calanthe in Calogynece. So that in this case, to 
unite the two genera would be to unite the two subtribes in one; 
and how many genera would follow suit it is difficult to say— 
that is, assuming Bentham’s views as to the gap which separates 
these two genera to be substantially correct. Structurally different 
they certainly are; and in this, as in the preceding cases, the 
differences are such as have hitherto been relied on as sufficient 
for generic distinction. If these structural differences are to be 
ignored because the plants possessing them can be hybridized 
together, the whole system of classification will be thrown into 
confusion. Indeed it would be kept in a state of perpetual fer- 
ment, as the advent of every uew bigeneric hybrid would furnish 
the opportunity of overhauling existing arrangements in order to 
bring them into harmony with new discoveries. 
It may be that some of these are already foreshadowed by the 
connections represented by the thin lines on the above diagram— 
crosses effected and capsules produced, but no seedlings raised. 
Future experiments in this direction may be attended with 
greater success, as has already been the case in several other 
instances. At present these cases can only be considered as 
indicating future possibilities; yet as capsules were produced, 
the fertilizing influence of the pollen cannot be doubted. These 
are not cases where, as Darwin puts it, the pollen had no more 
effect, when applied to the stigma, than so much inorganic dust. 
Passing them briefly in review, we may first take Acanthephip- 
