450 



ZOOLOGY 



SECT. 



arranged in two rows ; in the latter (the terminal vesicle) the 

 passage is lined by cells, and is thus intercellular, and there is a 

 thick muscular investment. The nephridia are abundantly supplied 

 with blood by means of nephridial branches of the ventral vessel. 



coe 



ext 



JL 



FIG 368. NephridiumofLumbricus (diagrammatic). a. ampulla between ciliated and non- 

 ciliated parts of the intracellular canal ; oil. ciliated part of the intracellular canal ; coe. 

 investment derived from the ccelomic epithelium ; gzL nephridiopore ; Ic. non-ciliated part 

 of the intracellular canal ; mes. septum ; nst. nephrostome ; t.v. intercellular canal of the 

 terminal vesicle. /. ///. the three principal loops. (From Meisenheimer, after Maziarski.) 



Reproductive Organs. The Earthworm is hermaphrodite. 

 There are two pairs of very small flattened testes (Figs. 366, 369, te t 



