112 LIGHT AND THE BEHAVIOR OF ORGANISMS 



dorsal surface. The eye-spot may also function in absorb- 

 ing the rays. 



(13) There is no evidence in these experiments bearing 

 on the question of anthropomorphic sensation. The results 

 do not exclude its presence. The reactions are due to 

 changes in light intensity, and every change, for all that is 

 known to the contrary, may cause a sensation. 



