Edward N. Wkmwuktu 



115 



that the standard deviation is the best method of comparison. The 

 interesting point is the relative constancy with which Line I breeds 

 true for fecundity. 



To show that this low type is absolutely distinct let us brieHy 

 compare Table I and Table II. While the mean for the low line is 



TABLE IL 

 Breeding Record of Line If. (Strongly Vigorous.) 



Pair .1 Pair B 



IK. 132 



i_. 



Pair C 

 98 



I 



Pair D 

 141 



140 



I 



^4 



Fs 

 Fo 

 Flo 



I 

 ItJl 127 



I I 

 142 138 



I 

 154 



I 

 136 



I 

 165 



I 

 157 



I 

 149 



"~1 



128 



I 



n 



134 117 



I I 

 127 141 



I 

 136 



I 

 156 



I 

 147 



1 

 138 



I 

 144 



110 



1 



131 



I 



I 

 112 



^ ^ ^ 



144 136 



I I 

 116 134 



I 

 127 



I 

 112 



I 

 141 



I 

 134 



I 

 129 



128 137 



I I 

 139 151 



I 

 114 



I 

 144 



I 

 152 



I 

 133 



I 

 156 



120 129 



I I 

 138 114 



I 

 141 



I 

 152 



I 

 127 



141 



I 

 132 



122 



I 



n 



116 129 



I I 

 101 145 



I 

 104 



I 

 94 



I 

 96 



I 

 97 



I 

 100 



152 



I 



147 160 



I I 

 126 154 



I 

 145 



I 

 139 



136 



I 

 132 



I 

 141 



135 



I I 



118 151 



I I 

 136 113 



I 

 162 



rL 



I 



157 



I 

 172 



I 

 180 



29*5 the mean for the high line is 135*86. The means of each genera- 

 tion when compared as in Line I are as follows : 



^3 Mean 128-75 



The mean for the entire line is 13586 and the standard deviation 

 183. This gives a coefficient of variability of 13-47, lower than the 

 coefficient for the low line although the range of variation is obviously 

 higher as evidenced by the standard deviation. Suffice it to say, 

 however, that the two lines are quite distinct, they overlap in nowise 



