290 
THE AMERICAN NATURALIST. 
[Vor. XXXV. 
The following constants of the frequency polygons have 
been determined (Davenport, '99) : 
1. Mode: Class of greatest frequency. 
5 
Mean: 77. RC. 
3. Standard Deviation, e = Ten 
n 
4. Coefficient of variability : CV. or X 100. 
un 
On 
TABLE VI. — LENGTH oF 
Lert WING. 
Cc 
. Probable error of Mean: P. E. M. [sub.] = + 0.6745 wa ; 
Co 
. Probable error of Standard Deviation : P. E.c [sub.] = + 0.6745 Vag 
AREA. 
Entire region 
Austroriparian . 
Appalachian . 
Campestrian . 
Sonoran . 
MATERIAL. 
168 males. 
70 males. 
35 males. 
27 males. 
36 males. 
112 females. 
31 females. 
25 females. 
24 females. 
32 females. 
Mope. 
98 mm. 
96 mm. 
98-100 mm. 
98 mm. 
I04 mm. 
102 mm. 
98 mm. 
98 mm. 
MEAN. STANDARD Dev. 
99.09 4- mm. 2.79 + mm. 
97.98 -- mm. 2.64 + mm. 
97.6 + mm. 2.04 + mm. 
96.64 + mm. 2.35 + mm. 
99.2 mm 2.45 + mm. 
97.68 mm 2.17 + mm. 
101.26 mm 2.45 + mm. 
99.75 mm 2.79 + mm. 
100.28 mm 2.90 + mm. 
98.19 + mm. 2.36 + mm. 
CV. of 168 males = 2.81 +. 
P. E. M. [sub.] 168 males = + 0.145. 
P. E. « [sub.] 168 males = + 0.1026 +. 
CV. of 112 females = 2.69 +. 
