7 
and the thorax is furnished with three pairs of legs, and 
usually with two pairs of wings, but sometimes these are 
absent. In the preceding stage, that of the pupa, in 
which development is taking place from the larval to the 
perfect stage, the insect is sometimes very similar in 
appearance to what it becomes in its perfect state, 
excepting that the wings and wing-cases are not fully de¬ 
veloped. This is the case with Aphides, Crickets, and 
Locusts, and some others, but with Moths and Butter¬ 
flies the pupa is motionless with the forming limbs 
enclosed in the case, that we know well as the chrysalis. 
With beetles the limbs are folded down and visible,—that 
is, not hidden by a thick case of hardened gummy secre¬ 
tion, as with the Moths just mentioned,—but they have no 
power of locomotion; and this is also the case with the 
pupae of the Wasps, Bees, Ants, Gallflies, Sawflies, and 
other very various insects forming the order of the 
Hymenoptera. With Two-winged Flies {Biptera) the 
pupa-case sometimes shows the shape of the coming 
limbs ; sometimes, a‘s with Onion Fly, is merely the 
hardened skin of the maggot, inside which the fly 
