134 DR. H. CRUGER ON THE FECUNDATION OF ORCHIDS. 
represented by the above little swellings, soon unite, in other plants . 
(Vanilla e. g.) they remain divided. This state of things (i. e. 
a part of the stigma standing on the posterior side of the flower) 
lasts comparatively a long time; it is only late that, by an elonga- 
tion of the axial part of the flower and a partial reversion, the 
stigmatic aperture is fixed on one side of the column, and a more 
or less considerable distance is created between its posterior lobe 
and the base of the labellum. 
This is, I believe, the common mode of development; the 
bottom of the flower, marked by the undeveloped stigmata, is 
carried up nearly to the top of the column. In Cypripediee it is, 
as far as I can see, rather different, the parts of the stigma being 
more developed (fig. 16, Selenipedium palmifolium, Rchb. fil., 
column; fig. 17, the same very young) and more distinct from 
each other, even at a very early period. As this is the only plant 
of that section which grows wild here, I cannot contrast this 
with other species*. 
The various appendages, excrescences, &e., which are observed 
on the full-grown column and labellum of so many Orchids are of 
very late origin, and prove their unessential nature in a morpho- 
logical point of view, whatever their physiological importance 
may be. 
From the above history of development I draw the following 
conclusions :— 
The eccentric development of the Orchid flower begins with 
the labellum; and it explains why, when the other perigonial 
leaves are connected, it remains free, and also the frequent 
connexion of the same with the column. The successive appear- 
ance of the parts of the stigma is another consequence of the 
above eccentricity. 
The part of the axis which bears the stigmata, and the organs 
immediately surrounding these, of which generally five, some- 
times four, do not make their appearance, is afterwards con- 
siderably lengthened, and at the same time the eccentric develop- 
ment causes a partial reversal of its apex, and generally the bent 
or prostrate position of the anther, originally erect. 
* This Selenipedium, which bears a small, very fragrant vanilla, is in all pro- 
bability always impregnated by insects. The labellum is, like some Aristolochia- 
flowers, constructed after the fish-pot system, 7. e. a funnel-shaped opening con- 
ducts into it, and insects find it difficult to escape through the same. The only 
other opening near the base of the labellum is partly closed by the sexual ap- 
paratus, and the insect has to force its way out there. 
