14 



LEON J. COLE 



d , e a. b 



Fig. 6 Plotting of number of times in 116 specimens in which a particular 

 arm occurred as the longest or one of the two longest (solid line) or as the short- 

 est or one of the two shortest (dotted line). 



fact that the mode falls at a instead of e, the curve for the 'long- 

 est' arm, represented by the unbroken line in figure 6, corres- 

 ponds closely to the curve for direction of locomotion in figure 

 4, while in a general way the curve for the 'shortest' arm (dotted 

 line) is the converse of these. 



If now we consider the mean lengths of the respective arms 

 of the 116 specimens, although the differences are very small, 

 and perhaps insignificant, nevertheless we find that their dis- 

 tribution corresponds to that just given, namely, e and a have 

 the greatest mean length, c and d the shortest. The exact fig- 

 ures are: 



^ Later computation of the probable error of the differences between the mean 

 lengths of the respective arms as here determined makes the value of these differ- 

 ences extremely doubtful. The striking fact is that, considering the often very 



