4OO O. E. PLATH. 



makers, not only store pollen under the conditions specified 

 by Sladen ('12, p. 44), but that toward the end of the summer 

 at the height ol brood-rearing prosperous colonies of these 

 two species store considerable quantities of pollen, in some 

 cases in shallow waxen bowls which are usually constructed near 

 the periphery of the comb. (cf. Fig. i). From these facts, it is 

 evident that Sladen's ('99 and '12) term Pollen-storers is of little 

 use in any comprehensive classification of the Bremidae. 



Furthermore, in regard to certain Pocket-makers, e.g., B. 

 americanorum and B. fervidus, it must be pointed out that the 

 habit of making pockets is resorted to only in the case of those 

 larvae which are destined to become workers, while the brood 

 which furnishes the other two castes (queens and males) is fed by 

 regurgitation; i.e., in the same manner as are those of the non- 

 pocket-making species, a fact to which the writer has called 

 attention in an earlier paper (cf. Plath '2i,a, p. 339). However, 

 since this method of feeding the male and queen larvae is not 

 employed at least in the temperate regions until toward the 

 end of the breeding season, and since the method by which these 

 Bremidae feed their worker brood is quite distinctive, it seems 

 best to retain the term Pocket-makers, unless future investigations 

 show that the use of this term is impracticable. 



We now come to Sladen's ('12) division of the Pocket-makers 

 into Pollen-primers and Carder-bees. As already mentioned, 

 Sladen later ('12, pp. 274-275) removed two species from the 

 Pollen-primers: but, as will be seen from the following observa- 

 tions, the term Pollen-primers will have to be completely rejected 

 as a subdivision of the Pocket-makers. 



In the fall of 1921 the present writer (cf. Plath '220, p. 34 and 

 '226, p. 195) made detailed observations on a large colony of 

 Brermis impatiens, a non-pocket-making species, and in this case 

 the egg-cells were regularly primed with pollen pellets before the 

 workers oviposited in them. 4 



Even more unsatisfactory is the term "Long-faced Humble- 

 bees" which Sladen ('12, p. 275) introduced later, since Bremus 

 mendax, which structurally belongs to an entirely different group, 



4 Incidentally this observation also shows that von Buttel-Reepen's ('03, p. 

 35) explanation of the pollen priming habit of bumblebees is incorrect (cf. also 

 Sladen, '12, pp. 274-275). 



