DECEMBER, 1909.] LHE ORCHID REVIEW. 355 
be watched. This being completed, the pencil may again be inserted, when 
the pollinia will touch the stigma, and some of the packets of pollinia will 
adhere to it. It may also be seen how one pollinium can be applied to 
many stigmas, leaving a few packets of pollen on each, and thus fertilising 
them. The whole forms a very beautiful example of adaptation, and it is 
significant that when a healthy plant of O. mascula was covered with a 
bell glass not a single pollinium was removed, and of course no seeds were 
produced. 
The action of the organs in Orchis mascula applies to various others, 
but with modifications in accordance with the different species and the 
insects which visit them, the latter including also flies and butterflies. The 
fact is that a great deal is now known about the fertilisation of our 
European Orchids, and it helps us in understanding many peculiarities of 
floral structure, all of which are seen to have their special significance. 
The genus Ophrys is remarkable for the resemblance of the lip to 
certain insects, hence the popular names of Bee, Fly and Spider Orchis. 
There are about thirty species, and most of them are remarkable for the 
possession of shining protuberances on the lip, whose function is not very 
well understood. The lip has no spur, and the glands of the rostellum are 
contained in separate pouches. Much less is known about the insects which 
fertilise them than in the case of Orchis, though from their highly complex 
structure it is clear that they are adapted for insect fertilisation. 
Darwin often watched the flowers of the Fly Ophrys, O. muscifera, but 
never saw them visited by insects, though Hermann Miiller once saw a fly 
seated on the lip, licking up the little drops of fluid which are occasionally 
exuded byit. Capsules are also rare, for Darwin once marked eleven plants, 
which only produced seven capsules between them, though he remarks that 
the flowers must be visited by insects, for he examined a number of plants 
‘during four successive years, and found that out of 207 flowers 88 had one 
or both pollinia removed. 
In the Bee Ophrys, O. apifera, however, the flowers are regularly self- 
fertilised, and this arrangement is effected by a very slight modification of 
structure. The caudicles of the pollinia are remarkably long, thin and 
flexible, instead of being rigid enough to stand upright, as in other species of 
the genus. The anther cells open soon after the flowers expand, and the 
thick ends soon fall out, the viscid discs still remaining in their pouches. 
The pollinia thus hang free in the air in front of the viscid stigmas, but are 
soon blown on to them by the wind, when they adhere and impregnation is 
effected. The result is that spikes of the Bee Ophrys often produce as 
Many seed-capsules as flowers, which affords a great contrast with the Fly 
Ophrys, which requires insect aid for its fertilisation. 
Darwin was so much surprised at the self-fertilisation of this species that 
