90 



A. S. PEARSE 



University, is said to have performed a series of experiments 

 in which colored bits of hydroid and bryozoan colonies were 

 used; he was unable to show that Libinia chose decorations 

 similar to the environment. 



The Larva of the Caddis Fly, Neiironia postica Walker. — 

 The case of this larva is built of slender bits of leaves finnly 

 bound together to form a brown cylindrical tube. This is a 

 familiar object to one who collects from the brooks about Ann 



nes 



GTI E£ /V 



Ti£D 



Q-REEM 



B 



Figure 3 — Plan of apparatus for testing the reactions of caddis fly larvae, A, 

 section; B, ground plan. 



Arbor, for the species is abundant. The dull brown of the case 

 harmonizes well with the muddy plant covered bottoms; hence 

 it is usually inconspicuous. 



A series of experiments was performed to ascertain w^hether 

 Neuronia larvae could be induced to select materials for the 

 construction of their cases that would match color of the back- 

 ground on which they rested. The color boxes described in 

 considering the reactions of the crayfish (p. 8i, Fig. i) were 

 used. 



On October 24, 1909, three larvae without cases were placed 



