222 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
distal end. The last section of each leg consists of the foot or 
tars^ls (plural tarsi) and comprises three joints: a long basal one 
bearing three soft pads beneath, a short second joint also bearing 
a pad, and a long and narrow distal joint bearing at its end a pair 
of sharp claws with a pad between them. The pads or cushions 
are called empodia (singular emiwdium) or pidvilli (singular pul- 
villus). They are very much larger in the Slant-faced and 
Spine-breasted Locusts which perch much more on plants than do 
the Band-winged group to which the Carolina Locust belongs. 
Since the typical number of segments in the insect tarsus is five, 
and the proximal segment in that of the Locust bears three 
pulvilli, it is regarded as three segments fused together, and an 
example of specialization of structure. The hind femora and 
tibiae are elongated and the femora greatly enlarged in com- 
parison with those of the other legs; this is a case of specialization 
for the purpose of leaping. In order to understand the reasons 
for the location of the tibial spines and their respective positions 
on the several pairs of legs, one should study a living Locust and 
watch its actions while it walks and leaps. Only in this way can 
one comprehend the action of the spines and spurs in conjunction 
with the claws to secure a good footing or aid in leaping or push- 
ing a way through vegetation. 
Fig. 13. — Part of right tegmen of Locust, showing venation, (.\fter Saussure.) 
Wings. — These are four in number: a long, narrow, unfolded 
anterior pair attached to the mesothorax; and a broad, posterior, 
metathoracic pair, folded in fan-like plaits. The front pair are 
thickened to form protective wing-covers or tegmina (singular 
tegmen). The hind ones are the flying organs, aided to some 
degree by the front pair. The wings are not appendages in the 
same sense as the legs, but are plate-like expansions of the body- 
