33 8 TRANS FOR MAT 10 NS OF INSECTS. 
them ; and they inflict great losses upon merchants, as well as 
upon householders. They do not lay their eggs one by one in 
different places, but they shut them up in a sort of capsule, which 
is rather leathery, and they carry it about with them until the 
young are about to escape ; they then help the little ones to get 
out of this bag, and at first are very attentive to them. 
The Blatta Americana is very common, and may be frequently 
noticed in the cargoes of ships. The engraving on page 337 
represents the larva and two adults of this kind. 
Blatta Orientalis , which is not so large as that just noticed, 
has its wings very badly developed. It is common in towns, 
and is particularly fond of hiding up in the cracks of chimneys, 
and of only appearing at night time. The larvae when first born 
are quite white, and resemble their parents in form, but change 
their skins six times before they become perfect. 
There is one great family of the Orthoptera the species of which 
are all carnivorous, and there are no insects which have such 
an extraordinary appearance as these Mantidce. Their strange 
attitudes, their great and strong limbs and leaf-like shapes, com- 
bined with the great slowness of their movements, do not make 
them look at all like bloodthirsty creatures. They have a narrow 
body, a very long prothorax, and a very movable head, which has 
large eyes and sharp and trenchant mandibles. They have 
large wings, front legs admirably adapted for seizing their prey, 
and the others are slender. The Mantidce are generally large 
and fresh-coloured, and sometimes the posterior wings, which 
are always more or less transparent, are very prettily ornamented 
and coloured. They crawl on bushes, where they remain per- 
fectly immobile hour after hour with the front of the body erect 
and with their front legs folded. This perfect quietude does not 
raise any suspicions in the insects which are flying about, but if 
an unfortunate fly comes too close the Mantis extends its foot 
rapidly and too surely. The Mantidce cover their eggs with 
a kind of capsule, which they hang on plants. 
The eggs are laid towards the end of summer, and the young 
larvae escape and grow like all the other Orthoptera. The species 
of this family inhabit the hot parts of Europe and the tropics, 
and wherever they are seen, their positions, apparently so medi- 
