ADDITIONAL DETAILS OF BASKET-LOADING PKOCESS. 21 
the planta is flexed the auricle is raised and its surface approaches 
the distal end of the tibia, its inner edge slipping up along the pecten 
spines and its outer hairy edge projecting into the opening which 
leads to the pollen basket. (See fig. 8, h.) With each upward stroke 
of the auricle small masses of pollen which have been scraped from the 
J plantar combs by the pecten are caught and compressed between the 
spiny surface of the auricle and the surface of the tibia above it. 
j The pressure thus exerted forces the pasty pollen outward and up- 
ward, since it can not escape past the base of the pecten, and directs 
it into the entrance to the corbicula. The outward and upward slant 
J of the auricular surface and the projecting hairs with which the outer 
edge of the auricle is supplied also aid in directing the pollen toward 
1 the basket. Sladen (1911) states that in this movement the weak 
j wing of the auricle is forced backward, and thus allows the escape of 
t pollen toward the basket entrance, but this appears both doubtful and 
'unnecessary, since the angle of inclination of the auricular surface 
j gives the pollen a natural outlet in the proper direction. 
If the corbicula already contains a considerable amount of pollen 
the contributions which are added to it at each stroke of the auricle 
come in contact with that already deposited and form a part of this 
mass, which increases in amount by continued additions from below. 
If, however, the corbicula is empty and the process of loading is just 
beginning, the first small bits of pollen which enter the basket must 
be retained upon the floor of the chamber until a sufficient amount 
has accumulated to allow the long overcurving hairs to offer it effec- 
tive support. The sticky consistency of the pollen renders it likely 
to retain contact with the basket, and certain structures near the 
entrance give additional support. Several small sharp spines, seven 
or eight in number, spring from the floor of the basket immediately 
within the entrance, and the entire lower edge of the corbicula is 
I fringed with veiy small hairs which are branched at their ends. 
(See fig. 3.) One large hair also springs from the floor of the basket, 
somewhat back from the entrance, which may aid in holding the 
i pollen, but it can not function in this manner until a considerable 
amount has been collected. 
As the pollen mass increases in size and hangs downward and back- 
i ward over the pecten and auricle it shows upon its inner and lower 
surface a deep groove which runs outward from the entrance to the 
basket. (See fig. 9, b.) This groove results from the continued im- 
pact of the outer end of the auricle upon the pollen mass. At each 
upward stroke of the auricle its outer point comes in contact with 
the stored pollen as soon as the mass begins to bulge backward from 
the basket. 
Although the process is a rather delicate one, it is entirely pos- 
sible so to manipulate the hind legs of a recently killed bee that the 
