502 Mr. C. R. Narajana Rao on the Anatomy of 



is a means of conserving water in tropical earthworms like 

 Phcretima is tlie more correct interpretation of their 

 function ; for if tliese structures were concerned in the 

 elimination of wjfste througli the gut, as is presumed to he 

 their function, then the chances of these waste particles heing 

 repicked up hy 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 typhlosole of 

 the Pheretima quite as numerously as in the other examples 

 of earthworms like Periclncta or Megascolex. INIore 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 

 ne|)hridia in Pheretima, that it is certainly doubtful whether 

 these digestive processes occur without the ferments being 



Text-fie. 2. 



A shows tlie velatiou of dorsal blood-ve.-^sel {IJ.B.) and the <ippendn,o-e 

 {E.A.). In B tlie relation of the supra-intestinal vessel {S.I.V.) 

 and the appendage is shown. C, D are hvpothetically derived I'runi 

 B. n.d., iie])hridial duct; S.\., septal nephridia; &ep.c., septal 

 canal ; S.l.E.C, ^upra-inte.>3tinal excretory canal. 



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

 be quite correct to ascril)e to these " eiiteronephric^' systems 

 an excretory function. If, in iidditiou to the histological 

 affinity between the enteric appendiiges of Drmvida and the 

 enteronephridia of Pheretima^ end)ryological evidence also 

 is forthcoming, then there can be no doubt about their 

 being an adaptation for the conservation of water. 



Vascular fiystem. — 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 with 

 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 



