74 



THE HUMBLE-BEE 



nest of ruderatus had six young larva?, varying from the 

 size of a lettuce seed to that of a mignonette seed in one 

 cell, 3 eggs in another cell, and 5 eggs in another. 



How Pollen is collected (pp. 20 to 24). Many varie- 

 gated loads of pollen collected by Bombi, consisting of 

 two or more kinds, were examined during 19 12, and they 

 showed clearly not only that the pollen is pushed into 

 the corbicula in the way explained on p. 22, but how the 

 load is built up. 



About 40 per cent of the loads brought home by a 

 colony of terrestris between July 15 and July 25 could be 



/, yellow 

 Z, white 

 3 , orange 



4, white 



5, orange 

 6 ,ye//ow 

 y, orange 

 8 ,y ei 'low 



ENTRANCE to 

 CORBICULA 



4, bright red 



ENTRANCE to CORBICULA 

 Fig. 34. 



/. Shallow load of pollen in the left corbicula of a worker of Bombus agrorum 

 captured at dead-nettle on July 4, 191 2. B, Section through a full load of 

 pollen in the left corbicula of a worker of B. terrestris taken on entering its 

 nest, July 23, 1912. 



The layers of the different kinds of pollen are numbered in the order in which 

 they were collected. Had the agrorum worker gone on collecting and gathered a 

 full load, the pollen shown in its corbicula would have occupied the region referred 

 to as "1, yellow" in Fig. B. 



seen at a glance to consist of two kinds of pollen ; in a 

 few of these, on closer examination, three or more kinds 

 were detected. 



Pollen -primers (p. 43). B. latreillellus was considered 

 to be a pollen-primer because pollen was found under the 

 eggs in a nest in an advanced stage examined in 191 i. 



