560 ORTHOPTERA. 



ing long excretory ducts, besides, also, often having long 

 pedunculated reservoirs. 



The number of chambers in the dorsal vessel is usually 

 eight. The respiratory system does not differ essentially from 

 that of other insects, though in the Acridii most of the trans- 

 verse anastomosing tracheae have large air-reservoirs, greatly 

 assisting in lightening the body for their long-sustained 

 flight. 



The urinary tubules are short and very numerous, from 

 twenty to one hundred and fifty and over, surrounding the 

 pylorus. The ovaries, two in number, consist of numerous 

 multilocular tubes, while the seminal receptacle consists of a 

 pedunculated vesicle, whose closed extremity is dilated into 

 a pea-shaped vesicle, forming the capsula seminis. In most 

 Orthoptera the testes consist of long fasciculated follicles sur- 

 rounded by a common envelope, and many have in addition 

 highly developed accessory glands, surrounding a short ductus 

 ejaculatorius. 



The larvae of the Orthoptera materially differ only in size 

 from the adult, and the pupae are distinguished from them by 

 having the rudiments of wings. They attain the adult state 

 by simple moultings. Several cases are on record of pupae 

 of grasshoppers being found sexually united. In 1867 Mr. 

 Trimen exhibited to the Entomological Societ} T of London "a 

 grasshopper of the genus Poecilocerus, of which he had found 

 the pupae in copula ; it was not an isolated case, for he had 

 seen hundreds of pairs of the nymphs at Natal." 



Some of the largest insects are included in this suborder, in 

 fact the majority are larger than those of other suborders, and 

 it will probably be found that many large grasshoppers ami 

 Mantidce will weigh nearly as much as any Goliath or Her- 

 cules beetle, the largest of insects. 



The Orthoptera range, in time, from the Carboniferous for- 

 mation ; and among the earliest forms are certain species of 

 .Blattarice, which are next to the group of the Xeuroptcra^ 

 the earliest known forms of insect life. In the Carboniferous 

 rocks they have rarely occurred, but the forms are most nu- 

 merous and best preserved in the Tertiary formation, espe- 

 cially in the Amber of Prussia. 



