ORTHOPTERA. 145 



joints of the tarsi is frequently flesliy or membranous *. Many fe- 

 males are furnished with a true perforator formed of two blades, fre- 

 quently inclosed in a common envelope, by means of which they de- 

 posit their eggs. The posterior extremity of the body, in most of 

 them, is provided Avith appendages. 



All Orthopterous Insects have a first membranous stomach or crop, 

 foUoAved by a muscular gizzard, armed internally with corneous 

 scales or teeth, according to the species ; round the pylorus, except in 

 the Forficulse, are two or more caeca, furnished at the bottom with 

 several small biliary vessels. Other vessels of the same description 

 arc inserted in the intestine near the middle. 



The intestines of the larva are similar to those of the perfect In- 

 sect f. 



All the known Orthoptera, without exception, are terrestrial, even 

 in their two first states of existence. Some are carnivorous or omni- 

 vorous, but the greater number feed on living plants. The species 

 that belong to Europe produce but once a year ; this takes place to- 

 wards the end of the summer, which is also the period of their final 

 transformation. 



We will divide the Orthoptera into two great familes J. 



* In the Acrydia, the under part of the first joint presents three pellets or 

 divisions, 



f M. Marcel de Serres professor of Mineralogy at Montpellier, has made the 

 anatomy of these animals his special study. According to him the Orthoptera with 

 cetaceous antennae, such as the Blattre, Mantes, Gryllo-talpse, Grylli, and Locustae, 

 have only elastic or tubular tracheae, which are of two kinds, arterial and pulmonai'y. 

 The latter alone distribute air throughout the body, after having received it from 

 the former. In Orthoptera with cylindrical or prismatic antennae, such as the 

 Acrydia and Truxales, the pulmonary tracheae are replaced by those that are vesicular. 

 They are furnished with cartilaginous hoops or movable ribs, and receive air from 

 tubular or elastic tracheae proceeding from the arterial tracheje. The nutritive system 

 is more or less developed and presents four principal modifications. The Grylli and 

 Gryllo-talpae have the advantage in this respect over the others. The crop is utricu- 

 liform and placed sideways, 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 Locustae 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 Blattae and Mantes present but two divisions ; 

 their nutritive system is otherwise the same. Whenever there is but a single testis, 

 the female has but oue ovary ; this is the case in all those which have vesicular 

 tracheae. Those which only have elastic or tubular tracheae, are furnished with two 

 testes and two ovaries. The vesiculae 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 

 Forficulae, 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. 



I Forming three sections in our Fam. Nat, du R^gn. Anim, The first is divided 



