PEEIPATUS. 



613 



beneath the oesophagus, but, soon diverging, remain widely separate 

 for the rest of their course. They are without ganglionic swellings ; 

 are connected together in their whole length by fine transverse 

 commissures, and finally unite with each other over the rectum at 

 the end of the body (fig. 416). The alimentary canal begins with 

 a muscular pharynx, and runs in a straight course. The anus is 

 terminal. A dorsal longitudinal vessel probably functions as heart. 

 [A pair of elongated unbranched glandular tubes, the salivary 

 glands, open into the buccal 

 cavity.] Moseley discovered 

 a well-developed tracheal 

 system, the stigmata of 

 which are distributed over 

 the whole surface of the 

 body. The tracheal trunks 

 are delicate tubes, which 

 are distributed upon the 

 viscera in fine tufts. Long 

 slime glands (considered 

 as testes by Grube) open 

 on the oral papillaa ; they 

 produce an exceedingly 

 sticky fluid, which the ani- 

 mal ejects when irritated. 

 The Onychopkora are, ac- 

 cording to Moseley, of 

 separate sexes. The ova- 

 ries are united to form 

 one structure placed in the 

 middle line on the dorsal 

 side of the intestine, near 

 the hind end of the body. 

 There are two long ovi- 

 ducts, which function as 

 uterus and open by a 

 common aperture on the 

 ventral surface close to the hind end of the body (fig. 416). The 

 testes are paired and egg-shaped, and lie towards the hind end 

 of the body. The vasa deferentia are coiled and unite to form a 

 common duct, which opens at the same place as do the female organs 

 (fig 417). The eggs develop in the uterus. 



33 



FIG. 416. Anatomy of a female Perlpatui (after 

 Moseley). F, Antennae ; , brain with the 

 ventral nerve cords (Vc); Ph, pharynx; D, 

 intestine ; A, anus ; Sd, slime gland ; Or, 

 ovaries ; Od, oviduct ; U t uterus. 



