ARTHROPOD A. 23 



which is connected with the stomach by a short segment of in- 

 testine, of small calibre, is large, and bent upon itself. The 

 terminal portion, or ' rectum,' is marked by longitudinal mus- 

 cular bands. 



Rolleston, p. 86 and p. 199. 



38. A Locust (Locusta), dissected to shew the female 

 generative system and the digestive system. 



The insect has been opened on its dorsal surface, most of 

 which has been removed. 



The ovigerous caeca form two bundles, one on each side. The 

 tubules composing them unite to form an oviduct. The two 

 oviducts join in the median line, and form the short and wide 

 vaginal canal which opens externally at the base of the large 

 ovipositor. Communicating with this canal by a short duct is 

 the ' sperm atheca' (pinned to< the left side), and also a long 

 thread-like accessory caecum (pinned to the right side). 



The digestive system of the insect has been arranged on the 

 right of the preparation. It closely resembles that of the Cock- 

 Roach; but the hepatic caeca are unusually large, and the 

 renal tubes are small. 



39. A Locust, dissected to shew the male generative 

 organs. 



The insect has been prepared in the same way as the last. 

 The testes are two large oval compressed bundles of sperm- 

 secreting tubules, one on each side of the body. Between them 

 is a mass of accessory glands, which have taken the form of 

 minute, much convoluted tubes. 



3. Order Diptera. 



40. A Common Flesh-Fly (Sarcophaga carnaria), dissected 

 to shew its digestive and female generative organs. 



The insect has been laid open along its dorsal surface. 



The alimentary canal has been pinned to the right, It 

 consists of a long tube, in which scarcely any difference between 

 stomach and intestine can be observed. The ovaries are seen 

 to be clusters of white caeca, arranged spirally. In this species 

 the female is viviparous. 



Packard on Insects, p. 408. 



