POLLEN MOISTENING. 25 
The writer is not prepared to deny the possibility that the surface 
of the chitin of the hind legs of worker bees may be moistened by 
the secretion of glands which lie beneath it, but he is convinced that 
any fluid thus secreted bears little or no relation to the cohesion of 
the pollen grains within the baskets. Sections and dissected prepa- 
rations of the hind legs of worker bees show certain large cells which 
lie within the cavity of the leg and which may function as secreting 
gland cells; but similar structures occur in even greater numbers 
within the hind legs of the drone and they are found within the hind 
legs of the queen. 
As has been noted, the extreme moisture of the plantar combs and 
of the tibio-tarsal articulation of the hind leg is readily understood 
when one recalls the manner in which moist pollen is compressed 
between the auricle and the tibial surface above it. 
From the account already given it is evident that, in the opinion 
of the writer, the mouth is the source from which the pollen-moisten- 
ing fluid is obtained. It is extremely difficult to determine with 
absolute accuracy the essential steps involved in the process of adding 
moisture to the pollen. In an endeavor to solve this problem the 
observer must of necessity consider a number of factors, among which 
may be noted (1) the location upon the body of the collecting bee 
of " moist " and of comparatively " dry " pollen, (2) the movements 
concerned in the pollen-gathering and pollen-transferring processes, 
(3) the relative moisture of those parts which handle pollen, (4) the 
chemical differences between the natural pollen of the flower and 
that of the corbiculse and of the cells of the hive, and (5) the observer 
must endeavor to distinguish between essential phenomena and those 
it which are merely incidental or accidental. 
In the first place it should be noted that the relative dampness of 
pollen within the corbiculse depends very largely upon the character 
of the flower from which the pollen grains are gathered. When 
little pollen is obtained it is much more thoroughly moistened, and 
| this is particularly true in cases when the pollen is all, or nearly all, 
I collected in the region of the mouth, the forelegs, and head. When 
I a bee takes pollen from white or sweet clover practically all of it 
f first touches the bee in these regions. It immediately becomes moist, 
{ and in this condition is passed backward until it rests within the 
baskets. There is here no question of "dry" and "wet" pollen, 
or of collecting movements to secure dry pollen from other regions 
of the body, or of the ultimate method by which such free, dry pol- 
len becomes moist. 
The sticky fluid which causes pollen grains to cohere is found upon 
all of the legs, in the region of their brushes, although the pollen 
combs and auricles of the hind legs are likely to show it in greatest 
abundance, since nearly all of the pollen within each basket has 
r 
