114 



Herbert Eugene Walter 



Secondly, the range between the maximum and minimum rates 

 of ten individuals in all intensities of non-directive light was 

 greater than the average range of rate of the same individuals 

 under different intensities of non-directive light. 



TABLE XXVIII 



The relative e^ect of individual behavior and light intensity on the range of rate of locomotion, 

 expressed in mm. per sec. 



A Variation of Individual Behavior 



Identification number of worm I I 



Maximum rate in all intensities given in B 2.58 i .67 2.00 i .67 2.17 2.08 2.20 



Minimum rate in all intensities given in B 0.92 0.67 0.92 0.83 1 .03 0.42 0.67 



1.78 1.82 1.58 

 o.28|o.28 0.75 



Range of rate i .66 i .00 i .0810.84 1. 14 i .66 1.53 1.50 i .54 0.83 



Range 0.83 = [1.66 (So. i or 6) — 0.83 (No. 10)] 

 B Variation in Different Light Intensities 



Light in candle meters o 0.94 11 '39 7^ '^^ ^55 •''7 



431 



Maximum rate for all worms given ; | 



in A 1 .58 1 .93 1 .92 1.77 , 1 .92 1 1.79 1 .87 2.00 j 1.55 



Minimum rate for all worms given ' ' 



in A 0.71 1.07 0.74 1.04 0.77 0.62 I -15 1-03 0.79 



Rangj of rate 0.87 1 0.86 1.18 0.73 i 1.15 | 1. 17 j 0.72 0.97 j 0.76 



Range 0.46 = [1.18 (11 cm.) — 0.72 (155 cm.)] 



Thirdly, with respect to clockwise or contra-clockwise turnings, 

 individual factors were found to be of more importance than 

 differences of intensity of non-directive light in determining the 

 direction of turning. 



It should be added that the ten worms concerned in the three 

 preceding tables were as similar in size and external appearance 

 as it was possible to select. 



A Cave Planarian. This specimen came from an Indiana 

 cave, where it probably had always lived in darkness up to the 

 time of its capture. When first made the subject of experiment, 

 it could be briefly described as a white worm, about 6 mm. in 



