On the Development of the ' Enteronephric ' 

 type of Nephridial system found in Indian 

 Earthworms of the genus Pheretima.' 



By 

 Karm Narayan Bahl, D.Sc, D.Phil. 



(Merton College, Oxford), 

 Reader in Zoology, Lucknow University, India. 



With Plates 5-7 and 8 Text-figures. 



Contents. 



PAGE 



1. Introductory ......... 49 



2. Historical ......... 51 



3. The Cocoon ......... 56 



4. General Outline of the Development of the Nephridial 



System in Pheretima ...... 59 



5. Development of the Primary Integumentary Nephridia . 65 



6. Development of the Primary Septal Nephridia . . 70 



7. Development of the Secondary Nephridia, Septal and 



Integumentary ........ 78 



8. Development of the Pharyngeal Nephridia and their 



Ducts .......... 83 



9. Comparison with the Development of ' Meganephric ' and 



the so-called ' Plectonephric ' Types of Nephridial 

 System ........ 



10. Phylogeny of the Oligochaete Nephridial System 



11. Material and Technique ..... 



12. Summary ........ 



13. References to Literature .... 



14. Explanation of Plates ..... 



85 

 87 

 95 

 98 

 100 

 101 



1. Introductory. 



In a previous paper in this journal (1) I described a new type 

 of nephridial system, which is found in Indian earthworms 

 of the genus Pheretima and which I called ' enteronephric '. 



