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 trachea? 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 

 P3'lorus. The ovaries, two in number, consist of numerous 

 mnltilocular tubes, while the seminal receptacle consists of a 

 pedunculated vesicle, whose closed extremity is dilated into 

 a pea-shaped vesicle, forming the capsida 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 

 ejacidatorins. 



The larva? 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 18G7 Mr. 

 Trimen exhibited to the Entomological Society of London "a 

 grasshopper of the genus Poecilocerus, of which he had found 

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

 seen hundreds of pairs of the lymphs 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 and 

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

 cules beetle, the largest of insects. 



The Orthoptera range, in time, from the Upper Devonian 

 formation ; and among the earliest forms were some Keuropter- 

 ous-like Locust ar in? and Blattaria*, which are likewise, 

 with the jSTeuroptera, the earliest known forms of insect life. 

 In the carboniferous rocks they become more numerous, but 

 the forms are most numerous and best preserved in the Ter- 

 tiary formation, especially in the Amber of Prussia. 



