21G 
Variation and Correlation in the Earthworm 
2. Total Number of Somites and Length of Body. 
In Table I. is shown the frequency distribution for the total number of somites 
in the body. 
TABLE I. 
Total Somites. 
Number of 
Somites 
1 
1 Frequency 
Number of 
Somites 
Frequency 
79 
1 
130 
1 
80—88 
— 
131 
4 
89 
2 
132 
7 
90—92 
— 
183 
4 
93 
1 
134 
3 
94 
— 
135 
5 
95 
1 
136 
6 
96—98 
— 
137 
9 
99 
2 
138 
10 
100 
1 
139 
6 
101 
— 
140 
5 
102 
2 
141 
17 
103 
— 
142 
27 
104 
3 
143 
21 
105 
1 
144 
24 
100 
1 
145 
37 
lUi 
z 
1 f fi 
IJfO 
108—112 
147 
31 
113 
114 
1 
3 
148 
149 
29 
26 
115 
3 
150 
51 
116 
151 
15 
117 
152 
15 
118 
2 
153 
12 
119 
154 
9 
120 
5 
155 
9 
121 
156 
10 
122 
1 
157 
4 
123 
2 
158 
124 
2 
159 
2 
125 
5 
100, 161 
126 
2 
162 
2 
127 
1 
163 
128 
5 
164 
1 
129 
4 
Total 
487 
This distribution is shown graphically in Fig. 1. There is hardly any doubt 
that the apparently multimodal condition of this histogram is due simply to 
the fact that we have a limited amount of material and a very wide range of 
variation. Our sample is not sufficiently large to cover smoothly the whole of the 
range. 
