INSTINCT AND INTELLIGENCE. 



sixteen little sheets of paper one under the other, with intervening 

 spaces at each part of it. Before the walls are further continued, 

 the first or uppermost stratum of comb is then fabricated and 

 attached to the sides by paper cement, and to the roof by a 

 colonnade of pillars. The empty cells of this stratum being ready, 

 the female big with eggs, deposits an egg in each, which is 

 retained there by being agglutinated to the roof and sides of the 

 cell : meanwhile, the workers continue their architectural labours, 

 first carrying downwards the paper walls as already described, 

 and next constructing the second stratum of comb and connecting 

 it with the first by a colonnade. 



94. It must be observed that in the society there is a well- 

 organised division of labour. One part of it is employed exclu- 

 sively in building, another in collecting food for the young, and 

 in tending and nursing them, and, in fine, the female in depositing 

 eggs in the cells. Since, therefore, a comparatively small pro- 

 portion of the colony is engaged in building, the progress of the 

 structure is necessarily slow, its entire completion being the work 

 of several months ; yet, though the result of such severe labour, it 

 merely serves during the winter as the abode of a few benumbed 

 females, and is entirely abandoned on the approach of the spring, 

 wasps never using the same nest for more than a single season.* 



95. The cells, which in a populous nest are not fewer than 16000, 

 are of different sizes, corresponding to that of the three orders of 

 individuals which compose the community ; the largest for the 

 grubs of females, the smallest for those of workers. The last 

 always occupy an entire comb, while the cells of the males and 

 females are often intermixed. 



96. Besides openings which are left between the walls of the 

 combs to admit of access from one to the other, there are at the 

 bottom of each nest two holes, by one of which the wasps uniformly 

 enter, and through the other issue from the nest, and thus avoid 

 all confusion or interruption of their common labours. 



97. As the nest is often a foot and a half under ground, it is 

 requisite that a covered way should lead to its entrance. This is 

 excavated by the wasps, who are excellent miners, and is often 

 very long and tortuous, forming a beaten road to the subterraneous 

 dwelling, well known to the inhabitants, though its entrance is 

 concealed from incurious eyes. The cavity itself, which contains 

 the nest, is either the abandoned habitation of moles or field 

 mice, or a cavern purposely dug out by the wasps, which exert 

 themselves with such industrj r as to accomplish the arduous 

 undertaking in a few days.t 



* Reaum. vi. G. f Kirby, vol. i. p. 426. 



156 



