540 THE FERTILISATION OF FLOWERS. [PART III. 
floor, which are sometimes covered with small drops of honey. 
They try for some time to escape by climbing up the vaulted sides 
of their prison towards the orifice that they entered by; at last 
after creeping beneath the stigma (st, 2, Fig. 180), they manage 
with a great effort to escape by one of two’small lateral openings 
(ex, 2) at the base of the lip; in doing so they smear one shoulder 
with a sticky pollen from the anther immediately above. In the 
Fia. 180.—Cypripedium Caleceolus, L. 
de —Flower, with its parts in their natural position, seen from in front and above. 
2.—Ditto, in longitudinal section, after removal of the sepals and the two superior petals. (The lip 
is bent slightly downwards, to show the opening ew clearly). 
3.—The essential organs from below. 
ov, Ovary ; 8, sepal ; Pe petal ; p’, labellum ; a, anther; a’, metamorphosed stamen ; st, stigma 
#, ‘entrance ’’; ew, ** exit.’ 
next flower, the bee, as it creeps under the stigma, leaves some pollen 
on its papille, which are long and point obliquely forwards ; then, 
squeezing itself again through one of the small orifices, it acquires 
another load of pollen: cross-fertilisation is thus effected regularly. 
The third anther (a’) is metamorphosed into a broad, purple-spotted 
lobe, which stands in the posterior half of the cavity of the lip and 
leaves only the small lateral orifices described above. The hairs, 
which are arranged in a broad band on the floor-of the labellum, 
seem to help the Andrene to climb up towards the orifices, besides 
