26 



COLORATION IN POLISTES. 



CORREIvATION BETWEEN SIZE OF METAMERIC SPOT AND WIDTH OF TERMINAL 



BORDER. 



In this determination males were included with the females. In Lot 

 I the yellow lateral area had entirely disappeared in second abdominal 

 segment, or had contracted to a small dot. In Lot 2 the yellow area 



Fig. 12.— Correlation between the markings of the ventral and the dorsal surfaces of the abdo- 

 men of the female. Lot i, continuous line, equals loo dark females, dorsal borders 

 narrow, lateral spot absent or tending to become obsolete. Lot 2, dotted line, equals 

 100 xanthic females,',borders broad, and large j'ellow or yellow and ferruginous blotch 

 . on the second abdominal segment. Classes c, f>, and a represent conditions of the 

 ventral surface. Second segment taken as standard, the melanism of the other 

 segments always being in advance of this. In c the lateral spot is large, and yellow. 

 or yellow with ferruginous margins. In 6 the lateral spot is small, yellow or brown, 

 and confluent with the border. In a lateral spot is absent. One square equals ten 

 individuals. 



Fig. 13.— Correlation between the markings of dorsal and ventral .surfaces of the abdomen of 

 the male. Lots i and 2, same as for the females. Cla.ss c, quadrilateral yellow area, 

 large, and covering all the ventral surface, excepting a narrow line next to the border. 

 *, yellow area reduced about one-half, a, yellow area obsolete. 



was large and edged with brown or black. With reference to width of 

 terminal border of second segment, measured in its widest medial zone, 

 we form these classes : Width of border in Class A, 0.3 to 0.5 mm. ; in 

 Class B, 0.5 to 0.7 mm. ; in Cla.ss C, 0.7 to 0.9 mm. 



