Some Phenomena of Regeneration in Limnodrilus 

 and Related Formst 



F. H. Krecker. 



With 2 figures in text and Plate XII— XIV. 



Contents. 



Introduction 383 



I. External Phenomena 385 



Materials and Methods 385 



Anterior Regeneration 386 



Movement of tlie Anterior End 388 



Minimal Size 390 



Posterior Regeneration 392 



The Intestine and Regeneration 397 



A. Posterior End 397 



B. Anterior End 405 



II. Internal Phenomena 407 



A. Posterior End 407 



The Glosure of the Wound and the Strand 407 



The Intestine 410 



The Proctodaeiim 414 



The Ectoderm and the Neoblasts and Formation of the Mesoderm . .417 



B. Anterior End 437 



The Neoblasts 437 



Other Structures including the Mesoderm 438 



Summary 444 



Literature List 44ö 



Explanation of Plates 448 



Introduction. 



In recent years a great amount of work has been done on the 

 regeiieration of the Tiibificidae aiid other microdrilous oligochactes, 

 dealing especially with the histogenesis and the more general differences 



^ A thesis presented to the faculty of Princeton University in partial 

 fulfillment of the requirement for the degree of Doctor of Philo.sophy. 

 Zeitschrift f. wissensch. Zoologie. XCV. Bd. 25 



