HABITATIONS OF INSECTS. 483 



such a precious material should be consumed. Bees, 

 therefore, in the formation of their cells have to solve 

 a problem which would puzzle some geometers, namely, 

 a quantity of wax being given, to form of it similar and 

 equal cells of a determinate capacity, but of the largest 

 size in proportion to the quantity of matter employed, 

 and disposed in such a manner as to occupy in the hive 

 the least possible space. Every part of this problem is 

 practically solved by bees. If their cells had been cy- 

 lindrical, which form seems best adapted to the shape 

 of a bee, they could not have been applied to each 

 other without leaving numberless superfluous vacuities. 

 If the cells were made square or triangular, this last 

 objection, indeed, would be removed ; but besides that 

 a greater quantity of wax would have been required, 

 the shape would have been inconvenient to a cylindri- 

 cal-bodied animal. All these difficulties are obviated by 

 the adoption of hexagonal cells, which are admirably 

 fitted to the form of the insect, at the same time that 

 their sides apply to each other without the smallest va- 

 cant intervals. Another important saving in materials 

 is gained by making a common base serve for two strata 

 of cells. Much more wax as well as room would have 

 been required, had the combs consisted of a single stra- 

 tum only. But this is not all. The base of each cell 

 is not an exact plane, but is usually composed of three 

 rhomboidal or lozenge-shaped pieces, placed so as to 

 form a pyramidal concavity. From this form it follows 

 that the base of a cell on one side or stratum of the 

 comb is composed of portions of the bases of three cells 

 on the other. You will inquire, Where is the advan- 

 tage of this arrangement ? First, a greater degree of 



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