2 ARTIFICIAL FOUNDATIONS ANd' THE BUILDING OF HONEY COMB. 



the comb cells upon it. The results were most conclusive 

 and are shown in the photograph that I hold in my hand, 

 and also in this sample of the comb. In this section of 

 comb it will be noticed that the black wax is drawn out into 

 the cell walls nearly or quite to the ends, and that the dark 

 color becomes less and less from the midrib outward until 

 it hardly shows at the extremity of the deeper cells. It 

 will also be noticed that in the section where a short starter 

 was used the blackened wax is extended downward for a 

 considerable distance and also outward into the walls of 

 the cells. As the color was imbedded into the wax of the 

 foundation the experiment shows conclusively that the wax 

 of the foundation is used in drawing out the comb, and in 

 extending the midrib. As all the foundations used had 

 short cell walls it was thought best next to determine 

 whether or not the bees used wax from both the midrib and 

 cell walls of the foundation or from the latter only. To 

 determine whether or not wax was used from the midrib, 

 samples of foundation were cast in plaster of Paris and 

 cross-sections made. Then other samples were given to 

 the bees for them to draw into comb. After the comb was 

 built, it was also cast in plaster and sectioned with a sharp 

 knife. Then careful measurements were made under a 

 camera lucida of the thickness of both the foundation 

 midrib and the midrib of comb built upon it. This was 

 done in many instances and with foundations of very 

 different weights, from the extra thin to the extra heavy. 

 As a result it was found that the heavier foundations 

 always had their midribs thinned, but never to the thinness 

 of that of naturally built worker comb. It was also found 

 that the foundations having midribs not exceeding .17 mm. 

 in thickness were usually thinned little if at all; and in 

 some cases where the midrib was thinner than in natural 

 comb the bees plastered on wax and made it unusually 

 thick.* [Show photographs and comb samples]. 



That the short cell walls of the foundation were also 

 thinned and used in comb building was evident at once on 

 examining the bases of the cell walls of comb on foun- 

 dation. See illustrations and comb samples. 



What was true of heavy midribs was also true here. 

 In cases where there was much wax in the short cell walls 



*It is possible that the thickened places were due to complete perforations of the midrib. 



