8 MONTANA EXPERIMENT STATION 
The first tarsal joint is somewhat enlarged and: greatly flattened 
and has on its inner surface a series of rows of regularly arranged 
stiff, bristle-like hairs used by the bee in cleaning itself and known 
as combs. The use of these combs in collecting pollen will be 
spoken of at length in the next section on the habits of bees. 
There remain a few words to be said in regard to the foot. 
There is an interesting structure known as the foot pad or pulvillus 
located between the two forked claws of the foot. This pad pro- 
duces a secretion of a sticky nature which enables the bee to cling 
to smooth surfaces. Its action is ,of interest. The bee, normally 
walking upon the tips of its claws, finds itself slipping, and in the 
struggle to stop itself the claws slip, and, in bending under, the 
sticky pad between them comes in contact with the surface. As 
the bee lifts the foot in taking another stride the claws serve as 
a pry and the pad is pulled loose, beginning at one edge as one 
would pull or peal up a freshly stuck postage stamp. In this way 
the bee is enabled to crawl on as highly polished a surface as a win- 
dow pane. 
The wings are four in number and are borne on the dorsal part 
of the first and second thoracic segments. They are membranous 
and are carried when at rest folded one pair above the other on the 
back of the body, thus enabling the bee to crawl into its cells with 
perfect ease. When spread, the two wings are fastened together 
by a series of hooks on the hind wing which hook into a fold on the 
fore wing, thus presenting a continuous surface to the air. Bees 
can fly forward and backward by adjusting the action of the wings. 
We will next take up the head and its appendages. The head 
is triangular in front view, with the mouth located in the lower an- 
gle. At the two upper angles are located the two large compound 
eyes, composed of a great number of hexagonal facets, covered 
with a fine coating of hairs. Besides these compound eyes the bee 
has three single eyes or ocelli, located in a triangle on top of the 
head, one in the center and to the front, and the other two placed 
laterally. On the front side of the head are borne the two feelers 
or antennae, which function, it is believed, as sense organs—smel] 
and possibly hearing. These consist of a long, basal segment, the 
scape, and a series of small segments, the flagellum, which articu- 
lates upon the scape. 
The mouth parts of the bee bear consideration in detail. There 
