300 THE AMERICAN NATURALIST. [Vol. XXXVI 1. 



bius breed in this latter location, since great numbers of very 

 small white individuals 3 to 8 mm. long are 

 to be found in the hiding places during the 

 months of July and August. 



I took the length of 200 individuals, 

 100 males and 100 females (Fig. 1). The 

 length was measured from the head be- 

 tween the bases of the antennae to the end 

 of the anal segment — not to the ends of 

 .' ■MmlrviSs! P ° lyg0n tne posterior legs. The polygons were 

 also drawn for the 100 males alone (Fig. 2), 

 for the 100 females (Fig. 3), and 

 for 100 mixed specimens, 51 

 males and 49 females, which 

 had been selected entirely at 

 random and so with no regard 

 to sex (Fig. 4). On this last 

 100 all the other determina- 



te 



this 



-eneous -roup. They are probably all adults 

 or nearly so. The longest male was 28 mm. 

 n '.'"'J ',,'aies long and the longest female was 25 mm. long. 



There are two apices for the length polygon, 

 test number of individuals (37) falling in the 20 mm. 

 I the next greatest (29) in the median class, 22 mm. 

 take but three individuals to level up the depression at 

 so that the polygon might be considered unimodal. It 

 o the right, due to the rejection of the smaller, younger 



the 



The polygon for the 100 males 



