ORTHOPTERA. o 
trial, even in their two first states of existence. Some are 
carnivorous or omnivorous, -but the greater number feed on 
living plants. The species that belong to Europe produce 
but once a year; this takes place towards the end of the sum- 
mer, which is also the period of their final transformation. 
We will divide the Orthoptera into two great families(1). 
anatomy of these animals his special study. According to him the Orthoptera 
with setaceous antennz, such as the Blatt, Mantes, Gryllo-talpe, Grylli, and Lo- 
custz, have only elastic or tubular trachez, which are of two kinds, arterial and 
pulmonary. The latter alone distribute air throughout the body, after having re- 
ceived it from the former. In Orthoptera with cylindrical or prismatic antenne, 
suchasthe Acrydia and Truxales, the pulmonary trachez are replaced by those that 
are vesicular. They are furnished with cartilaginous hoops or movable ribs, and 
receive air from tubular or elastic trachee proceeding from the arterial trachee. 
The nutritive system is more or less developed and presents four principal modi- 
fications. The Grylli and Gryllo-talpz have the advantage in this respect over the 
others. The crop is utriculiform and placed sidewise, while in the others it is in 
the direction of the gizzard. Here the hepatic vessels are inserted separately: in 
the former, that insertion is effected through the medium of a common deferent 
canal. The Truxales and Acrydia, although approximated to the Locuste by 
their digestive system, still differ from them in their superior hepatic vessels, the 
extremity of which is no longer furnished with secretory vessels, and which form 
cylindrical and elongated canals, but not widened sacs. The intestines of the 
Blatte and Mantes present but two divisions; their nutritive system is otherwise 
the same. Whenever there is but a single testis, the female has but one ovary; 
this is the case in all those which have vesicular trachee. Those which only have 
elastic or tubular trachez, are furnished with two testes and two ovaries. The 
vesicule destined to lubricate the common spermatic canal are either double or 
single, according to the presence of one testis or two. The common oviduct of 
the females is also provided with a lubricating vesicle. The Forficule, on which 
he is silent, are removed from all other Insects of the same order, according to 
Baron Cuvier, by the absence of superior hepatic vessels. For the anatomy of 
these latter Insects we refer the reader to the Memoirs of MM. Posselt and Leon 
Dufour. With respect to the power of flight, it is evident that it is much greater 
in the Acrydia and Truxales, than in the other Orthoptera. 
(1) Forming three sections in our Fam. Nat. du Régn. Anim. The first is di- 
vided into four families corresponding to the genera Forficula, Blatta, Mantis, and 
Phasma. The second comprises two families constituted by the genera Acheta 
and Locusta. The third section forms another family, having for its type the 
genera Pneumora, Truxalis, and that of Gryllus, Fab., or the Aerydium, Geoff. 
See also for further details on the Insects of this order, the Memoirs of the Aca- 
demy of St Petersburg, 1812. 
This division into two great families is confirmed by their anatomy, the Insects 
of the first having tubular trachee only, and those of the second such as are vesi- 
cular. 
