502 Mr. C. R. Nara3-ana Rao on the Anatomy of 



is a means of conserving water in ti'0])ioal earthworms like 

 Plieretim.a is tlie more correct interpretation of their 

 fnnction; for if these strnctures were concerned in tlie 

 elimination of waste tbrongh the ^nt, as is presumed to he 

 their function, then the chances of these Avaste particles being 

 rei)icked up by the chloragogenic or yellow cells of the 

 alimentary epithelium will have to be accounted for. The 

 yellow cells are }n-esent in the gut-wall and typhlosolc of 

 the Pherethna quite as numerously as in the other examples 

 of earthworms like Perichata or Megas-colex. More than 

 this, the volume of the toxic products entering that part of 

 the gut where the digestion and absorption of food take 

 place must be so large, judging from the number of septal 

 upphridia in Pherethna, that it is certainly doubtful whether 

 these digestive processes occur without the ferments being 



Text-fio'. 2. 



A shows the relation of dorsal blood-vessel (D.B.) aud the appendage 

 (jE.A.). Ill B the relation of the supra-intestinal vessel (S.I.V.) 

 and the appendage is shown. C, D are hypothetically derived from 

 B. ii.d., nephridial duct; »S'.A'., septal nephridia ; Sep.c, septal 

 canal; S.l.E.C, supra-intestinal excretory canal. 



destroyed. On the^^e physiological bases alone, it may not 

 be quite correct to ascribe to these "enteronephric" systems 

 an excretory function. If, in addition to the histological 

 affinity between the enteric appendages of Draivida and the 

 cnteronephridia o£ Fheretima, embryologieal evidence also 

 is forthcoming, then there can be no doubt about their 

 being an adaptation for the conservation of water. 



Vascular System. — The last hearts are in segment 9 and 

 the most anterior ones in segment 5. The dorsal vessel is 

 thickest over the region of gizzards and is connected witli 

 the lateral longitudinal vessels by secondary vascular com- 

 missures in somites 9, 8, and 6. The lateral longitudinal 

 vessels, whenever present in this species, rarely extend 



