CHEMICAL SENSITIVITY OF TAESI OF PYRAMEIS 



65 



After access to water, the butterfly was allowed to rest for a 

 minimum interval of fifteen minutes, whereupon trials were 

 resumed. The specimen was again placed in the holder with its 

 four feet upon the screen platform and carefully observed for one 

 minute. As before, however, there was never any indication of 

 response during this preliminary trial. Next, the dry cotton 



Fig. 2 Photograph showing holder employed in experiments on stimulation 

 of individual tarsi. Note the appearance of the proboscis, P, in the unstimu- 

 lated animal. 



swab was applied to the tarsus, but this now failed to elicit even 

 a single partial extension of the proboscis. The dry swab was 

 followed by a swab saturated with distilled water. Prior to the 

 administration of water, this had produced a very high per cent 

 of response. It now failed to produce a response in nearly every 

 trial. An additional stimulus was, therefore, employed, viz., a 

 sw^ab saturated with a IM saccharose solution. To this stimulus 



