ENTOMOLOGY. 659 



dations to extend the cell walls and the comb midrib. This belief 

 was shown to be well founded by a simple experiment, during- which 

 sheets of thin foundation rendered black by the addition of lanipldack 

 were employed. It was found that the wax used both for the exten- 

 sion of the midrib and th«> formation of cell walls contained lampblack. 



The author measured a number of artificial foundations of comb 

 midrib built upon such foundations and a natural midril) of comb. 

 The evidence confirms that obtained by weighing the same structures, 

 that heavy foundations are somewhat thinned by the bees in construct- 

 ing comb upon them, but that these fovmdations are not thinned in 

 any case to the lightness of natural comb. 



To determine whether the use of artificial foundations results in 

 thicker cell walls in the comb, experiments were made with several 

 kinds of foundation, measurements being made with the camera lucida 

 and a compound microscope. The cell wall in natural worker comb 

 varied from 0.045 to 0.07 mm., with an average of 0.06 mm. None of 

 the artificial foundations gave as thin cell walls except, perhaps, the 

 thin and extra thin super foundations. The author concludes from 

 this experiment that it is a mistake to make deep cells in artificial 

 foundation unless their walls can be rendered as thin as those of the 

 natulral cell walls. The only cell walls which were brought to the thin- 

 ness of the natural comb were those which were built on foundations 

 with a light base and with little wax in the cell walls. To study the 

 efl'ect of foundations upon the resulting comb, pieces of natural comb 

 and comb on different kinds of foundation were cut into l)locks of known 

 area and weight, the cell walls were then removed from the midribs, 

 and the two portions weighed separately. The weights of the midribs 

 and cell walls of natural comb were compared with corresponding parts 

 of comb from artificial foundations. The evidence leads to the con- 

 clusion that heavy foundations result in combs which are heavier than 

 the natural combs, and that the increased weight is due both to thicker 

 midribs and thicker cell walls, but more especially to the latter. The 

 evidence shows also that if the cell walls are high the}^ are not often 

 thinned by the bees in constructing the comb. 



Studies of the extent to which the use of foundation lessens the secre- 

 tion of wax by bees were made by a similar series of weight deter- 

 minations. The evidence furnished by the weights of -iO samples of 

 comb indicates that the wax secretion by bees is not any more influ- 

 enced by furnishing them with a heavy foundation than by the use 

 of a light foundation. 



With regard to the methods of using foundation in sections, the 

 author found that by using a long piece of foundation gradually taper- 

 ing to a point, with a broad base attached to the upper edge of the 

 section, the bees showed a tendency to form worker comb throughout. 



15440 — No. 7 



