236 Professor Edward B. Poulton on the 
apparatus has been evolved by the agency of this 
principle rather than by that of natural selection. 
Others may draw opposite conclusions from the same 
observations, which I therefore set forth by themselves, 
apart from general theoretical considerations. I believe 
that the observations themselves are correct, and that the 
uncertain points are stated with due caution. 
PEZOTETTIX PEDESTRIS. 
Avaust 29, 1§95.—I watched a pair of Pezolettix 
pedestris continuously for about an hour and a quarter, 
viz., from about 2.30 p.m. to 3.45. ‘The day was fine and 
the sun powerful, and this had been the case for many 
days previous to the 29th. 
When first observed, the male was seated on the back 
of the female, the anterior legs being clasped round her 
prothorax, but every now and then one of them was 
passed round her head and sometimes even over the eye. 
''wice the female was seen to raise her leg and sweep the 
male’s leg off her face. The male’s second pair of legs 
apparently clasped the posterior part of her first 
abdominal segment, fitting im between the femora of 
the female’s third pair of legs and her body. he male’s 
third pair of legs were not used for maintaining his 
position, but were held either horizontally or inclining 
upwards posteriorly, the tibiz forming an acute angle 
with the femora, and the tarsus being raised so as to form 
an acute angle with the tibiz. Jor nearly the whole of 
the time of observation the male’s third legs were jerked 
up and down alternately, the strokes not succeeding each 
other very rapidly. No audible sound was produced. 
No corresponding movement was seen on the part of the 
female. 
Jn attempting to copulate, the male let himself down, 
sometimes on one side and sometimes on the other, suffi- 
ciently far to bring the extremity of the abdomen below 
that of the female. The terminal segments of the male’s 
abdomen were then turned upwards and inwards towards 
the external generative aperture of the female, with which 
the everted male organs were brought into contact. No 
movement of the corresponding female parts was seen, 
but contractions of the whole abdomen occasionally took 
