REPRODUCTIVE SYSTEM. 



297 



club-shaped digestive outgrowths are connected. These 

 seem to have a pancreatic function. 



(3) The hind gut (proctodaeum) is lined by a chitinous 

 cuticle. It is convoluted and divided into narrow ileum, 

 wider colon, and dilated rectum with six internal ridges. 

 From the beginning of the ileum, the excretory Malpighian 

 tubules are given off. 



Respiratory System. — The tracheal tubes, which have ten 

 pairs of lateral apertures or stigmata, ramify throughout the 

 body. 



Circulatory System. — The chambered heart lies along the 

 mid dorsal line of abdomen and thorax. It receives blood 

 by lateral valvular apertures from the surrounding pericardial 

 space, and drives it forwards by a slender aorta. The blood 

 circulates, however, within ill-defined spaces in the body. 



The Excretory System consists of sixty or so fine (Mal- 

 pighian) tubules, which rise in six bundles from the beginning 

 of the ileum, and twine through the " fatty body " and in 

 the abdominal cavity. 



Reproductive Syste. 



Of the Male, 



Of the Female. 



The testes are paired organs, sur- 

 rounded by the fatty body below 

 the 5th and 6th abdominal 

 terga. They atrophy in the 

 adult. 



From the testes, two narrow ducts 

 or vasa deferentia lead to two 

 seminal vesicles. 



These seminal vesicles (the " mush- 

 room-shaped gland ") open into 

 the top of the ejaculatory duct. 



This duct opens on the loth sternum. 

 Beside the aperture there are 

 copulatory structures (gona- 

 pophyses). Withthe ejaculatory 

 duct a gland is associated. 



The ovaries are paired organs, in 

 the posterior abdominal region, 

 each consisting of eight ovarian 

 tubes. These are bead-like 

 strings of ova at various stages 

 of ripeness. 



From the ovarian tubes of each side, 

 eight eggs pass at a time into 

 a short wide oviduct. 



The two oviducts unite and open in 

 a median aperture between the 

 8th and 9th abdominal sterna. 

 Beside the aperture are hard 

 structures (gonapophyses) which 

 help in the egg laying. Here 

 also a pair of " coUeterial " 

 glands pour out their cementing 

 secretion by two apertures. 

 The spermatheca is a paired 

 sac with a single aperture on 

 the gth abdominal sternum. 



