334 
Psyche 
[September-December 
•» 
Fig. 44 through 47. Graphs of four unitary stridulations in lateral view 
during an interaction between two males, one attempting courtship (illus- 
trated, the other responding with the male interaction “rasp” or “femur- 
shake with wing-striking” (not illustrated). The frames of Fig. 44 are 
partly reproduced in Figs. 8-43 and the angles relative to the tegminal 
dorsal line are drawn in Fig. 8. Alternate frames were measured, the 
abscissa points are frame numbers converted to msec. The far (left) femur 
could only be measured when out of synchrony with the near (right) femur, 
i. e., on the downstroke. Note: a) either femur can lead on the downstroke, 
lagging behind the other by 20 to 30° and 12 to 24 msec; b) high amplitude 
sound occurs only on the downstroke ; and c) total silence occurs if both 
femora pass one another at angles above 70° (see Fig. 48), but if one femur 
fails to complete the full upstroke, the sound is not interrupted. 
