460 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



ure 15), 5 inches X 6 inches, which formed the sides of the chamber. 

 When one of the glass sides had been firmly pressed against the median 

 "stops," the two wooden strips {h, Figures 17, 15) were pressed against 

 the pane and clamped in position by steel clamps (w, Figure 15), one jaw 

 of which rested in a vertical groove (^, Figure 17) cut in the edge of the 

 end piece, as shown in section at m (Figure 15). When both panes were 

 thus clamped in position, a fairly tight chamber ^ inch thick and 5 

 inches X 6 inches in area was completed. This was nea^rly filled with 

 earth. All wooden pieces were infiltrated with paraffin to prevent warp- 

 ing, as the base of the nest was occasionally placed in water to keep the 



TABLE V. 



No. of the Colony 



Kind of Nest 



No. of observations .... 



Av. no. of workers in colony 



Per cent of workers building 

 Av. no. of winged queens in 



colony 



Per cent of winged queens 



building 



Av. no. dealated queens in 



colony 



Per cent dealated queens 



building 



earth damp. In case either pane of glass needed cleaning, the nest 

 was laid on its side with that pane uppermost, and the plate was then 

 exchanged for a clean one by un clamping the wooden strips of that 

 side. 



2. Observations. — The colonies observed in this activity were espe- 

 cially small, so that it is not safe, perhaps, to lay much stress on the 

 results, except in relation to other work on this subject. I give them, 

 therefore, merely as additional evidence. 



From these experiments (Table V) ^ I found, again, that the per 

 cent of individuals engaged in this activity is, as a rule, small, and is 

 independent of the number of individuals present in the nest. In 

 most cases (colonies 54, 53, and 42) the per ceirt was smaller in the 



' Table V was constructed in substantially the same manner as Table IV 

 (p. 457). 



