INSECTS IN RELATION TO PLANTS 271 
which entangle pollen grains. These are combed out of the 
gathering hairs by means of special pollen combs (Tig. 263, 
C, pc) on the inner surface of the proximal segment of the hind 
tarsus, the middle legs also assisting in this operation. [trom 
these combs, the pollen is transferred to the pollen baskets, or 
corbicula (Fig. 263, A, co), of the outer surface of each hind 
tibia; by crossing the legs, the pollen from one side is trans- 
ferred to the corbiculum of the opposite side, the spines (ss) on 
the posterior margin of the tibia serving to scrape the pollen 
from the combs. Arriving at the nest, the hind legs are thrust 
into a cell and the mass of pollen on each corbiculum 1s pried 
out by means of a spur situated at the apex of the middle tibia 
(Fig. 263, B, s), this lever being slipped in at the upper end 
of the corbiculum and then pushed along the tibia under the 
mass of pollen; the spur is used also in cleaning the wings, 
which explains its presence on queen and drone, as well as 
worker, but the pollen-gathering structures of the hind legs 
are confined to the worker. This is true also of the waz- 
pincers of the hind legs (Fig. 263, 4, C, w) at the tibio-tarsal 
articulation; these nippers are used by the worker to remove 
the wax plates from the abdomen. 
For cleaning the antenne, a front leg is passed over an 
antenna, which slips into a semicircular scraper (Fig. 263, 
D, a) fashioned from the basal segment of the tarsus; when 
the leg is bent at the tibio-tarsal articulation, an appendage, or 
velum (v), of the tibia falls into place to complete a circular 
comb, through which the antenna is drawn. This comb is 
itself cleaned by means of a brush of hairs (b) on the front 
margin of the tibia. A series of erect spines (sp) along the 
anterior edge of the metatarsus is used as an eye brush, to 
remove pollen grains or other foreign bodies from the hairs 
of the compound eyes. The labium, hypopharynx and max- 
ille (Fig. 54) are exquisitely constructed with reference to 
gathering and sucking nectar; the maxille are used also to 
smooth the cell walls of the comb; the mandibles (Fig. 45, C), 
notched in queen and drone but with a sharp entire edge in the 
