560 ORTIIOPTERA. 



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 ovei-, 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 capsnJa seminis. In most 

 Orthoptera the testes consist of long fasciculated follicles sur- 

 rounded by a common envelope, and man}- have in addition 

 highly developed accessory glands, surrounding a short ductus 

 ejacnkUorius. 



The larvn3 of the Orthoptera materially differ only in size 

 from the adult, and the pupa^ are distinguished from them by 

 having the rudiments of wiugs. They attain the adult state 

 by simple moultings. Several cases are on record of })upae 

 of grasshoppers being found sexually united. In 18G7 Mr. 

 Trimen exhibited to the Entomological Society of London "a 

 grasshopper of the genus Pacilocerus, of which he had found 

 the pup;e in cojvda ; 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 mau}^ large grasshoppers and 

 Mantidm will weigh nearl}* 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 Neuroptera^ 

 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 tho Tertiary formation, espe- 

 cially in the Amber of Prussia. 



