10 



LEON J. COLE 



for Specimen 2; for No. 3 it is arm d; and so forth, as indicated 

 in the last column to the right in the table. This column shows 

 that in six of the ten individuals used, the preponderating direc- 

 tion of crawling was toward arm e; in three it was toward arm 

 d; while in one arm a was most often in advance. In no case 

 was the preponderating movement toward either h or c. This 

 tendency to move in the direction of arm e is plainly indicated 

 when the records for the ten individuals are added, as shown in 

 the bottom row of the table. The same fact is represented 

 graphically by the solid line in figure 4, where these totals are 

 plotted; the ordinal spaces in this case being given a valuation 

 of twenty trials in order to make the two curves comparable. 

 The 'mode,' as before, is clearly at e; but in this case the 'curve' 

 drops off smoothly and with remarkable symmetry on the two 

 sides. 



In figure 5 these valuations are referred to a diagram of a 

 starfish, where the symmetry of the 'curve' in figure 4 shows 



Fig. 4 Plotting of number of times each radius and interradius was in advance 

 in the crawling experiments. Dotted line from data given in table 1 ; solid line 

 from data of table 2. 



Fig. 5 Diagram of starfish, showing the number of trials accredited to each 

 arm as 'director' (cf. fig. 4 and table 2). A A, line of bilateral symmetry with 

 respect to the records; an approximately equal number of trials fall to each side. 

 The line BB has 347 records 'ahead' of it and only 152 'behind.' 



