FRANDSEN. — REACTIONS OF LIMAX MAXIMUS. 



221 



and the total negative responses of the left side (column 7), — these 

 responses being necessarily right-hand movements. The total movement 

 in degrees to the left (column 10) was likewise obtained by adding the 

 total negative responses of the right side and the positive responses of the 

 left side. Column 1 1 gives the total number of animals used in each series. 

 In the region of negative phototaxis, the total positive and negative 

 angular migrations, and the average negative phototaxis of all the series 

 (1-7, inclusive) when the riglit and left sides respectively were turned 

 toward the light, were as follows. 



TABLE XVI. 



Sum of the Responses of Right and Left Sides when Phototaxis 



is Negative. 



This shows on the whole a less sensitive right side, or, to put it differently, 

 a more marked negative phototaxis of the left side. How is it when the 

 animals become positively phototactic ? Table XVII. gives the average 

 positive response of the right and left sides for series 8 to 18, including 

 series la, 8a, da, and 10a. 



TABLE XVII. 



Sum of Responses of Right and Left Sides when Phototaxis 



is Positive. 



Here an asymmetrical response is less strongly marked. The left side, 

 however, appears on the average to be somewhat more strongly attracted 

 toward the light. The results prove that the asymmetry in response of the 

 right and left sides cannot be wholly due to a tendency to move toward 



