TARSAL CHEMORECEPTORS OF BUTTERFLIES 



189 



the proximal segment of the tarsus formed the great shaft of 

 the leg, running from the femur almost or quite to the substrate, 

 while the second, third, fourth, and fifth tarsal segments, by 

 virtue of their shortness, formed a flexible portion of the leg 

 which was to a greater or less extent in contact with the substrate 



Fig. 4 Photograph of Pyrameis in holder, showing position of legs on a hard 

 substrate, t, tibia; o, proximal segment of tarsus; s, distal segments of tarsus. 

 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. 



(fig. 4). In the great majority of cases, only the three or four 

 distal segments were actually in contact with the substrate, and 

 there were times when fewer than this number were affected. 

 When all four of the distal segments were in contact with the 

 substrate, the distal portion of the proximal segment might also 

 be brought in contact with it. But only in rare instances, when 



