358 C. H. TURNER. 



inner side, the roach would swing around on the underside of 

 the maze until it could catch hold of the edge with the first and 

 second feet of what had been the inner side. It then would 

 remove the third foot of what had been the outer side and move 

 along in the opposite direction. It was a common thing for 

 roaches ten to twelve millimeters long to rest suspended beneath 

 the maze with the claws of the third pair of legs clinging to the 

 edge of a runway and with the other feet braced against its 

 undersurface. 



Frequently a roach was noticed making its toilet while sus- 

 pended from the maze by one foot. On one occasion I observed 

 a roach, about seventeen millimeters long, which was hanging 

 suspended from the maze by its right third leg, brace itself by 

 bringing the left third leg in front of the other and clinging to 

 the edge of the maze with both feet. 



TOILET-MAKING HABITS. 



I stated above that frequently movements to solve the maze 

 are interrupted by toilet-making activities. Since most people 

 look upon roaches as nasty things, this toilet-making behavior is 

 a surprisingly interesting instinct. The mouth-parts, the first 

 pair of legs and the third pair of legs are the instruments used 

 by the roach in making its toilet and each has its special work. 

 In cleaning the head and the base of the antennae the first pair 

 of legs are used in much the same way that a cat uses her forelegs 

 in washing her face. One of the flexed legs is rubbed downward 

 over the head and the base of the antenna? one or more times and 

 then cleaned by the mouth-parts. This may be repeated several 

 times. 



As would be naturally expected, the antennae, which seem to 

 be the most important sense organs of the roach, are cleaned 

 oftener than any other part. If you are standing a short distance 

 from a roach that is resting on the maze, you will notice an 

 antenna suddenly bend downward into the mouth. Slowly it 

 straightens itself while the constantly moving mouth-parts 

 remove the dirt. The next moment the antenna of the other 

 side suddenly bends downward and is treated in the same way. 

 One day a rather keen observer, who was visiting my insectary, 



