Reactions of Isopods to Light 



281 



tightly fastened around the lower end of the lamp-container and 

 closely drawn around the illuminated end of the tank as well as 

 the edges of the partition, so as to form a light-tight hood between 



Fig. 6 Diagram showing in vertical section the apparatus used in experiments with vertical illumina- 

 tion. C, sheet-iron roof of lamp container; C-S, cloth screen; Zr, inner tank; LC, lamp container; 

 or, outer tank; P, partition; S, horizontal screen; 5L, vertical slate; T, table; A', place of observa- 

 tion. 



