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 tlie hind legs of worker bees show certain large cells wdiich 

 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 

 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 wdien the pollen is all, or nearly all, 

 collected in the region of the mouth, the forelegs, and head. ^Vllen 

 a bee takes pollen from white or sweet clover practically all of it 

 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 



