2 INSECTA. 
The Orthoptera(1) undergo a semi- metamorphosis, of which 
all the mutations are reduced to the growth and development 
of the elytra and wings, that are always visible in a rudi- 
mental state in the nymph. As both this nymph and the 
larva are otherwise exactly similar to the perfect Insect, they: 
walk and feed in the same way. 
The mouth of the Orthoptera consists of a labrum, two man- 
dibles, as many maxille, and four palpi; those of the jaws 
always have five joints; whilst the labials, as in the Coleoptera, 
present but three. The mandibles are always very strong 
and corneous, and the ligula is constantly divided into two or 
four thongs. ‘The form of the antenne varies less than in the 
Coleoptera, but they are usually composed of a greater num- 
ber of joints. Several, besides, their reticulated eyes, have 
two or three small, simple ones. The inferior surface of the 
first joints of the tarsi is frequently fleshy or membranous(2). 
Many females are furnished with a true perforator formed of 
two blades, frequently enclosed in a common envelope, by 
means of which they deposit their eggs. The posterior extre- 
mity of the body, in most of them, is provided with append- 
ages. 
All Orthopterous Insects have a first membranous stomach 
or crop, followed by a muscular gizzard armed internally with 
corneous scales or teeth, according to the species; round the 
pylorus, except in the Forficule, are two or more cxea, fur- 
nished at the bottom with several small biliary vessels. Other 
vessels of the same description are inserted in the intestine 
near the middle. 
The intestines of the larva are similar to those of the per- 
fect Insect(3). . 
All the known Orthoptera, without exception, are terres- 
(1) In this order and in those of the Lepidoptera, Hymenoptera, and Rhipip- 
tera, as wellas in the Apterous Hexapoda, there are no aquatic species. 
(2) Inthe Acrydia, the under part of the first joint presents three pellets or 
divisions. 
(3) M. Marcel de Serres, professor of Mineralogy at Montpellier, has made the 
