FERTILIZATION OF ORCHIDS 189 
disc, at the base of the pollen masses, and now 
that it is withdrawn you see one of these masses, 
known as the pollinium, attached to the pencil. It 
has detached itself from the flower, and stuck itself 
firmly on to the pencil by means of its sticky base, 
and now you see it standing almost upright, with a 
slight backward slope. Watch what it does. It 
gradually bends over and forward, until the pollen 
mass is practically horizontal, pointing forward. 
Suppose a bee visits Orchis mascula to get honey out 
of its spur. It settles on the labellum, pushes its 
head into the mouth of the flower, extends its pro- 
Fig. 55.—FERTILIZATION oF ORCHIS MASCULA (PENCIL 
EXPERIMENT). 
a, First position of pollinium!; 5, second position of same. 
Pp Pp j P 
boscis, and sucks up the delicious fluid. In the 
meantime, the pollen mass, or masses (for sometimes 
both masses become detached), have attached them- 
selves by their sticky foot firmly to the head of the 
bee, probably right on one of its eyes. The bee 
leaves the flower with the pollinium on its head, and 
as it is proceeding to another flower for more honey 
the pollinium turns forward as on the pencil. When 
the bee puts its head into the next flower, it has to 
push the pollen mass against the stigma, and thus 
the flower gets fertilized. Orchids don’t desire to 
fertilize themselves, and such a device as the one I 
have illustrated is resorted to in order to secure cross- 
