REACTIONS TO LIGHT IN PLANARIA MACULATA 91 
wae, 
Fig. 10 Diagrams illustrating process of orientation in specimens with left 
eye removed, when illuminated laterally from the left, i.e., the ‘blind’ side. The 
arrows indicate the direction of the rays of light. A, orientation by means of 
‘wandering reflex;’ 1, 2, 3, and 4, successive positions of animal; 1, 2, 3’, 4’, 5’, and 
6’, successive positions of the animal if it is moving rapidly; B, orientation by 
means of ‘twisting reflex;’ 1 to 4, successive positions of specimen. Insert C rep- 
resents a diagrammatic cross-section of specimen in B through the plane a-b; R, 
position of rhabdomes which are illuminated in such reactions. 
THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 31, No. 1 
