^^ PHYLUM PLATYHELMmTHE8 203 



of chitinous bristles. Among the ordinary epidermal cells there 

 are in the Polycladida numerous cells containing short rod-like 

 bodies— the rhahdites {rh.) ; in the other orders of the Turbellaria 

 these rhabdite-forming cells are sunk deeply within the paren- 

 chyma, and, in the Rhabdocoela, have very long ducts, formed of 

 processes of the cells, by means of which the rods, together with a 

 viscid matter, reach the exterior at certain points of the surface, 



Fig. 206. — Caryophyllaeus. 



d. Q. vitelline duct ; d. st. vi- 

 telline glands ; e. excretory 

 pore ; k. mobile organ ; od. 

 oviduct ; ov. g-ermarium ; p. 

 cirrus ; r. s. rcceptaculum sc- 

 minis ; t. lobes of testes ; v. d. 

 vaa deferens ; v. s. vesicula 

 seininalis ; to.g.o. female aper- 

 ture. (After Leuckhai-t.) 



Fig. 207.— Gyrocotyle (Amphiptyches). 



e. 0. excretory opening ; m. o. male opening ; 

 n. longitudinal nerve ; n'. anterior nerve- 

 ring ; n. r. posterior nerve-ring ; o. opening 

 of uterus ; o. ovary ; o'. receptaculum 

 ovorum ;^. base of cirrus ; r. s. receptaculum 

 semi n is ; t. s. o. opening of vagina; s. 

 sucker ; t. testes ; ut. uterus ; v. s. vesicula 

 seniinalis ; yk. vitelline glands. ( After 

 Spencer.) The end here directed downwards 

 represents the scolex-end of other Cestodes. 



Fig. 208.— 

 Archigetes. 



(After Leuckhart ) 



chiefly around the anterior extremity. The function of these 

 rhabdites is not in all cases certain ; they have been supposed to 

 add to the sensitiveness of the parts in Avhich they are situated 

 after the fashion of hairs or nails, or to have a skeletal function. 

 In the Rhabdocoela and Tricladida they undoubtedly aid in 

 adhesion, and probably have the function of assisting in the 

 entanglement and capture of food. In certain of the Turbellaria 



