OBSERVATIONS ON BUMBLEBEES. 7 1 



posterior legs together." Hoffer (1882/83, I, p. 16), Wagner 

 (1907, p. 98), and Prison (1917), on the other hand, state that the 

 bumblebee removes the pollen with the middle pair of legs, and 

 this agrees with my own observations. Prison (pp. 283-284) ' 

 describes the process as follows: "After the pollen-containing 

 cocoon has been found, th'e worker stands on the edge facing 

 away from the cocoon, and inserts her hind legs down into the 

 cocoon; then she proceeds by a quick, slicing downward move- 

 ment of the middle pair of legs, to remove the pollen from the 

 corbicula." It is difficult to conceive how bumblebees could 

 deposit pollen in the manner described by Coville (p. 200), and 

 Sladen (p. 46), and it seems probable therefore that these two 

 authors overlooked the rapid movement of the second pair of legs. 



X. ON THE BEHAVIOR OF POLLEN-LADEN BUMBLEBEES IN 



LATE FALL. 



Wagner (1907) claims that bumblebees suffer a great reduction 

 of instincts toward the end of the breeding season. As one of the 

 proofs for this assertion, he states that in late fall pollen-laden 

 bumblebees return to the nest, but leave again without depositing 

 their pollen. Although I had about 75 bumblebee colonies under 

 observation during the summers of 1921 and 1922, I was unable 

 to observe any such behavior, and this leads me to believe that 

 there were other reasons than those given by Wagner (p. 190) 

 why his bees left without depositing their pollen. 



XI. THE CAPPING OF HONEY CELLS. 



Hoffer (1882) and Sladen (1912), the two foremost European 

 authorities on the biology of bumblebees, differ as to whether 

 bumblebees cap their honey. Hoffer (I, p. 39) has the following 

 to say concerning this question: "1st das Honigtopfchen voll, 

 so wird sehr haufig ein stumpf-kegelformiger Deckel dariiber 

 gebaut, der aber in der Mitte eine ganz kleine Oeffnung hat, so 

 dass also niemals vollstandig gedeckelte Honigzellen angetroffen 

 werden, wie sie die Bienen haben." Sladen (p. 53), on the other 

 hand, says : " In a favourable season a populous colony may have 

 all the vacated cocoons, amounting to over 400, filled with thick 

 honey and sealed over with wax." Observations made on Bremtis 

 ternarius (by Putnam, 1865), Bremus auricomus (by Prison, 1917), 



