86 KARM NAKAYAN BAHL 



formation, and that is why they do not develop any funnel 

 at all. The septal nciphridia, on the other hand, develop from 

 the intersegmental nephridial mass of cells which possesses 

 a ' furmel-cell ', and so we get septal nephridia with funnels 

 developing from this source. 



This meganephric, or rather the paired condition in the 

 embryo, is superseded by, and is assimilated into, the adult 

 condition which is ' enteronephric ', so far as the septal and 

 pharyngeal nephridia are concerned ; but is ' micronephric ' 

 and diffuse so far as the integumentary nephridia are concerned. 

 It cannot be called ' plectonephric '. If the place of opening 

 of the nephridia be taken into consideration we can divide the 

 nephridia into two groups : those that open to the outside on 

 the surface of the body-wall and may be termed ' dermo- 

 nephric ' or ' exonephric ', and those that open into any part 

 of the gut and may be called ' enteronephric '. The former 

 category will include the ordinary ' meganephridia 'of Lum- 

 bricus, as well as the integumentary micronephridia of 

 Pheretima and the plecto-nephridia of other worms. The 

 latter term, i. e. enteronephric, will comprise the septal and 

 pharyngeal nephridia of Pheretima, the ' pharyngeal 

 tufts ', the ' peptonephridia ' or ' sahvary glands ' of such forms 

 as Megascolides, Periscolex, and Enchytraeids, 

 and the anal nephridia of Octochaetus and A 1 1 o - 

 lobophora antipae (14). 



Comparing the nephridial development of Pheretima 

 with that of the plectonephridia of Megascolides (17) 

 and Mahbenus (8), we have to note that, while in the latter 

 the whole system results from the breaking up and branching 

 of the first pair of nephridia, in Pheretima there is no such 

 branching and breaking up, and all the nephridia, septal and 

 integumentary, appear independently of one another. More- 

 over, the first pair of nephridia in Megascolides and 

 Mahbenus have ' funnels ' which persist in Megascolides 

 but degenerate in Mahbenus, while Pheretima has no 

 ' funnels ' even on its initial pair of integumentary nephridia. 



In my previous paper (1), from a study of the structure of 



