252 'Journal of Comparative Neurology and Psychology. 



M, for the purpose of discovering whether the larvae in presenting 

 their negative phototactic reaction, would allow themselves to be 

 driven into the shallow water. By means of a hole in the bottom 

 of the box, the water could be withdrawn very gradually (a few 

 drops a minute), so that if the larvae persisted in remaining in the 



Fig. 7. Diagram of apparatus as set up to test the extreme phototactic reactions, leading, in the 

 case of fourth and fifth-stage lobsters, to fatal results. L, source of light; M, reflecting mirror; A, end 

 of box adjacent to "window;" B, end of box not covered with water, where the lobsters were stranded. 

 In the cover of the box are shown the sliding partitions. 



shallow area, they would, in the course of a few minutes, be 

 stranded on the dry bottom. Ten fourth-stage lobsters were first 

 used for experiment and the results, ascertained by counts made 

 as in all other cases, were as follows : (The arrow shows the direc- 

 tion of the light coming through the end window of the box, while 

 the numbers at the top of the columns represent the division areas 

 of the box) : 



The results of this experiment and of several others similar to 

 it, show, that out of a total of twenty-four larvae which gathered 



