G4 



KARM NARAYAN BAHL 



like the primary nephridia, but have a more or less scattered 

 arrangement. They may appear either on the dorsal or on 

 the ventral side of the primary nephridia (Text-fig. 1 c). They 

 arise in connexion with the setal sacs, and one can very often 

 see a string of cells running from the rudiment of a secondary 

 nephridium in the coelom to the epidermis alongside a setal sac. 



Text-fig. 2. 



c.c 



Diagram showing the formation of nephrithal rows of teloblasts and 

 the intersegmental position of large 'funnel-cells'. ?«., mouth. 

 For lettering see Text-fig. 3. 



The pharyngeal nephridia of the fourth, fifth, and the sixth 

 segments make their first appearance in a manner similar to the 

 primary integumentary nephridia, although the former lag behind 

 in development, the integumentary nephridia gro"s\-ing faster 

 than the pharyngeal. Amongst the pharyngeal nephridia 

 themselves the nephridia of the sixth segment develop faster 

 than those of the fifth, and these, in their turn, faster than 

 those of the fourth. The first pair in each of these segments 

 originates from the ectodermal nephridial row, and has a long 

 terminal duct which meets the wall of the pharynx ventro- 



