360 C. H. TURNER. 



Tactile. The tactile sense of the roach is remarkably keen. 

 Even a slight jar to one portion of the maze is responded to by a 

 sudden more or less prolonged halt on the part of the roach on a 

 distant point on the maze; and this is true when neither antennae 

 nor palpi are touching the maze and even when the antenna? 

 have been amputated. 



Olfactory. On the maze itself no conclusive evidence was 

 obtained of the use of this sense. True the antennae were almost 

 continually waving in space, but it was impossible to determine 

 whether they were seeking olfactory or tactile stimuli. The trap 

 used in capturing the roaches for these experiments was similar 

 to the Graham roach trap described by F. L. Washburn in the 

 Journal of Economic Entomology for June, 1913; but I used an 

 eight-ounce bottle instead of an Erlenmeyer flask and no hairs 

 were placed around the apex of the smaller cone. A trap baited 

 with dry oatmeal flakes would capture practically no roaches; 

 but one baited with oatmeal steeped in stale beer invariably 

 captured large numbers. It seems reasonable to assume that 

 it was the sense of smell that enticed the roaches into the trap. 



Auditory. Up to now my notes on the auditory sense are 

 exceptionally non-committal. On the maze roaches seem to 

 pay no attention to sounds produced continuously. For ex- 

 ample, a loudly ticking clock was placed two feet from the maze; 

 but to its sounds the roaches made no responses whatever. To 

 certain suddenly produced sounds they responded by halting 

 suddenly, to others they made no response. For example: 

 one day while some tinners were fixing the guttering of a nearby 

 house, to certain noises made by the tin the roaches were quite 

 responsive; but, when, by means of a small bell, I attempted to 

 demonstrate that they respond to suddenly produced sounds, 

 the roaches made absolutely no external responses. By means 

 of a Galton whistle and other methods an attempt is being made 

 to solve the problem; but, up to now, no satisfactory solution 

 has been reached. 



Vision. That the roach possesses vision of some kind is 

 "certain, and at times a roach would act as though it were able 

 to distinguish objects at a distance. Recall roaches jumping 

 from one runwav to another a distance of an inch and a half- 



