164 THE ORCHID REVIEW. [JUNE, 1922. 
FERTILISATION OF CEPHALANTHERA. 
NDER the above title an article by Colonel M. J. Godfery, F.L.S., is 
published in the last. issue of the Linnean Society's Journal (vol. xlv. 
511). It is a very interesting account of a primitive form of Orchid, for 
Cephalanthera not only shows us how cross-pollination was possible before 
a rostellum had yet come into existence, but it also enables us to’ form some 
idea as to how that unique organ first came to be evolved. 
The method by which most Orchids are fertilised is sufficiently well 
known to require but a brief explanation. Projecting forwards over the 
edge of the stigma is the rostellum, or viscid gland, to which are attached 
the pollinia. When a suitable insect visits the flower the rostellum adheres 
to its head, and thus causes the insect, when leaving, to carry away the 
pollen. ‘But when,” says Col. Godfery, ‘‘we try to find out how 
Cephalanthera is fertilised, we are met at the outset by an apparently 
insuperable difficulty—there is no rostellum whatever. The conspicuous 
flowers are well-suited to attract insects, but there is a complete absence of 
the usual mechanism for the removal of the pollinia.”’ 
Reference is made to Darwin’s investigations of the fertilisation of 
C. grandiflora, and to his belief that Cephalanthera was a degraded 
Epipactis, that is, an Epipactis which has lost its rostellum, and with it the 
possibility of cross-pollination by insects. Col. Godfery next gives his 
observations regarding the anther. ‘If the anther was pressed back on its 
hinge, it at once resumed its former position when released .... What 
is the object of this elastic spring-hinge?’’ Attempts to remove the 
pollinia by means of a dry camel’s-hair brush were unsuccessful, but when 
the brush was first caused to sweep gently upwards along the middle of the 
stigma it came out with both pollinia attached. ‘ The object of the elastic 
hinge now became apparent. The anther must be pressed against the back 
of the stigma, so that the pollinia may project far enough forward to ensure 
that an insect, retreating backwards from a flower, after smearing himself 
with the viscid matter of the stigma, shall also brush against the pollinia. 
These at once adhere by their convex centres, their ends pointing forwards. 
It is these projecting ends which come into contact with the stigma of the 
next flower visited.” 
Cephalanthera is certainly a very ancient genus, and one which shows 
us the earliest method of cross-pollination in the Orchidacee, before 4 
rostellum had been evolved. That C. ensifolia and C. rubra are both 
entirely dependent on insects for pollination is proved by the fact that if the 
flowers are not so visited, no seed capsules are produced. ‘‘C. grandiflora 
can be fertilised in this manner,” states Col. Godfery, “but this does not 
seem to happen very often, for it is rare to find flowers from which the: 
