TARSAL CHEMORECEPTORS OF BUTTERFLIES 



191 



had been amputated. It should be borne in mind, therefore, 

 that these were operated specimens. The results of these experi- 

 ments are presented in table 4. 



It will be noted that there was not a single response when the 

 swab was held 1 mm. anterior to the proboscis. Moreover, 



Fig. 5 Photogniiih of the same specimen of Pyrameis as sliown in figure 4, 

 showing the proboscis, /), completely extended as a result of contact between 

 the left second tarsus, and a cotton swab saturated with a 1 M saccharose solu- 

 tion. This photograph has been slightly retouched in order to bring out more 

 clearly parts which were not quite in focus or which, because of their light color, 

 did not show distinctly. 



there was but one response when the swab was held 1 mm. 

 from the ventral surface of the tarsus. When, however, the 

 swab was apphed directly to the ventral surface of the tarsus, 

 there was not a single failure to respond, and in twenty of the 

 twenty-three trials the proboscis was completely extended. 



