242 yourjial of Comparative Neurology and Psychology. 



indicate that the early fourth-stage lobsters show a slight tendency 

 to remain in the more brio;htly illuminated areas. 



Cflj^ 2. Phototactic reaction — August 7, 5:30 p.m. Ten earlv 

 fourth-stage larvae were placed in box B and the end window of the 

 box was opened to the diffuse light of the west window. As has 

 been explained, this box was so constructed that in a moment 

 glass plates could be slid through the cover, and mto such position 

 that thev would divide the floor area of the box between the ends 

 into four equal parts. Beginning with the end toward the light 

 these may be numbered i, 2, 3, 4, respectively, and the results 

 showing the imprisonment of the larvae in two instances, may be 

 recorded as follows: 



5 

 7 

 9 



7 



28 



In the second of these instances an acetylene light was used, the 

 intensity being diminished by inserting a red glass between the 

 burner and the window in the end of the box toward the light. 



