146 Insect Architecture. 



When they have in this manner worked the bottoms of the 

 first row of cells into the required forms, some of the nurse- 

 bees finish them by imparting a sort of polish, while others 

 proceed to cut out the rudiments of a second row from a fresh 

 wall of wax which has been built in the meanwhile by the 

 wax-workers, and also on the opposite side of this wall ; for 

 a comb of cells is always double, being arranged in two 

 layers, placed end to end. The cells of this second row are 

 engrafted on the borders of cavities hollowed out in the wall, 

 being founded by the nurse-bees, bringing the contour of all 

 the bottoms, which is at first unequal, to the same level ; and 

 this level is kept uniform in the margins of the cells till they 

 are completed. At first sight nothing appears more simple 

 than adding wax to the margins ; but from the inequalities 

 occasioned by the shape of the bottom," the bees must accumu- 

 late wax on the depressions, in order to bring them to a level. 

 It follows accordingly that the surface of a new comb is not 

 quite flat, there being a progressive slope produced as the 

 work proceeds, and the comb being therefore in the form of a 

 lens, the thickness decreasing towards the edge, and the last- 

 formed cells being shallower or shorter than those preceding 

 them. So long as there is room for the enlargement of the 

 comb, this thinning of its edge may be remarked ; but as soon 

 as the space within the hive prevents its enlargement, the 

 cells are made equal, and two flat and level surfaces are 

 produced. 



M. Huber observed, that while sketching the bottom of a 

 cell, before there was any upright margin on the reverse, 

 their pressure on the still soft and flexible wax gave rise to 

 a projection, which sometimes caused a breach of the parti- 

 tion. This, however, was soon repaired, but a slight promi- 

 nence always remained on the opposite surface, to the right 

 and left of which they placed themselves to begin a new 

 excavation ; and they heaped up part of the materials between 

 the two flutings formed by their labour. The ridge thus 

 formed becomes a guide to the direction which the bees are 

 to follow for their vertical furrow of the front cell. 



We have already seen that the first cell determines the 



