LEON J, COLE 



Fig. 3 Diagram of starfish crawling with three rays in advance 



IV. EXPERIMENTAL RESULTS 



1. Direction of locomotion 



In recording the individual trials in the experiments note 

 was made as to which arnx was directed toward the observer 

 at the beginning of the trial (i.e., the orientation of the speci- 

 men) and the part of its own body which was in advance as it 

 crawled. Since the orientation was changed in the successive 

 trials, the actual direction of movement was of course different 

 if the animal crawled with the same ray in advance. The orien- 

 tation at the beginning of the trial was recorded that it might 

 serve as a check on the uniformity of the environment; but since 

 the position of original orientation showed no effect in the results 

 of the experiments, it will not be further considered, and we 

 need concern ourselves only with the direction of advance with 

 respect to morphological relations. This was recorded only for 

 radii and interradii. There were bound of course to be some 

 cases of doubt; but these were comparatively few, and an error 

 here would be of little consequence, since it would merely throw 

 the reading to the next radius or interradius to right or left, and 

 these would tend to balance each other. That such was actu- 

 ally the case is indicated by the evenness of the totals for the 

 different adjacent positions as shown in table 1, which presents 



