Ernest Warren 
143 
TABLE XIV. 
Frontal Breadth of Parents and Ratio of Offspring. 
Offspring : Ratio. Uuit = 10 thousandths of Frontal Breadth. 
Ol 
io 
-19-9 
o 
©^ 
©J 
1 
;^ 
Oi 
'i> 
©-> 
r 
©J 
C5 
SP 
Weighted 
Number 
of 
Families 
00 
9> 
9> 
J?' 
9> 
'i 
1 
1 
"5! 
Mothers 
i4.-o~u-9 
3 
2 
0 
1 
6 
1 
1.5-0— 15-9 
.3 
8 
5 
4 
10 
13 
7 
7 
0 
4 
61 
9 
16-0— 16-9 
1 
5 
6 
2.5 
27 
33 
23 
13 
4 
1 
138 
25 
17-0— 17-9 
2 
2 
10 
18 
8 
12 
11 
4 
1 
68 
11 
18-0— 18-9 
1 
2 
7 
12 
18 
17 
14 
4 
75 
11 
19-0— 19-9 
1 
2 
6 
1 
10 
2 
20-0— 20-9 
7 
2 
0 
1 
10 
1 
Totals 
1 
11 
18 
50 
63 
70 
75 
53 
20 
3 
4 
368 
60 
j3 15 
w 3 a 
is 55 
O (M 
p II 
.2 !^ 
s II 
a 
(10) The Variability among the Members of a Brood. 
We have already seen that the variability of the race is in no way smaller than 
in sexual animals. It is now necessary to discuss the variability in the individual 
family. 
The standard deviation for all the families containing 7 or more members 
was calculated and the mean is given in the last column but one of the accom- 
panying table (Table XV.). 
TABLE XV. 
Genus 
Dimension 
Variability 
Parents (60) 
weif^hted with 
their fertility 
Offspring 
(368) 
Arrays 
Mean of the 
S.D.'s of all 
families over 
and including 7 
Total No. of 
families in which 
the S.D. was cal- 
culated 
Hyalo- 
pterus 
Breadth 
unit = '01 mm. 
Length of Antenna 
unit = "01 mm. 
Ratio 
unit = -010 of Frontal 
Breadth 
S.D. 
Percentage 
S.D. 
Percentage 
S.D. 
Percentage 
2-7682 
57-4 
9-2262 
59-4 
1-4974 
66-5 
2-9647 
63-6 
10-9367 
50-1 
1-8363 
54-2 
2-7930 
56-9 
9-8884 
55-5 
1-6797 
59-2 
1-5890 
100 
5-4839 
100 
-9953 
100 
22 families and 
190 individuals 
Daphnia 
Ratio 
unit =-002 of Body 
Length 
S.D. 
Percentage 
2-2208 
57-4 
2-9503 
43-2 
2-6104 
48-8 
1-2747 
100 
22 families, 
95 individuals 
Mean of the percentages 
60-2 % 
50-3 % 
55-1 % 
100 
