TARSAL CHEMORECEPTORS OF BUTTERFLIES 



185 



The results of the experiments on the mutilated butterflies 

 are presented in table 2. 



Several facts are brought out clearly by these data. In 

 position 1 the number of responses was reduced almost to zero. 

 It is beyond the scope of the present paper to discuss the signif- 

 icance of this result. It will be treated fully in a subsequent 

 paper. In position 2 the animals behaved essentially as before 

 the operation. In position 3 there was a considerable diminution 

 in the number of responses. My note-book indicates that this 

 may have been due in part to operative causes, for in several 



TABLE 2 

 Pyrameis 



instances slight bleeding and subsequent coagulation caused the 

 coil of the proboscis to become stuck together. However, the 

 question whether the antennae, to the exclusion of the tarsi, 

 account for the discrimination between distilled water and 

 applejuice, is answered clearly. For, in spite of the marked 

 diminution of responses in position 3, the animals still gave 

 nearly four times as many responses in this position as they 

 did in position 2. Clearly, therefore, the tarsal organs are able 

 to distinguish between contact with distilled water and contact 

 with applejuice, and hence, as previously contended, they must 

 be contact chemoreceptors. 



