450 F. H. Krccker, Some Pheuomena of Regeneration in Limnndrilus etc. 



Fig. 17. Gross section of the body takcn fartlier forward than was fig. 16. 

 Circular muscle fibrils present. Zeiss oc. 2. ob. 2 mm oil imm. 



Fig. 18. Shows character of the cctoderm cells over the scar region at the 

 posterior end of the body about 36 hrs, after the Operation when the neoblasts 

 are present. Longiscction. Zeiss oc. 3, ob. D. 



Fig. lü. Longisection of a worm killed tluee days after the t)i)eration. 

 Posterior end of the body. Zeiss oc. 3, ob. D. 



Fig. 20. Advanced stage in the metamorphosis of the ectoderm over the 

 scar region at the posterior end of the body, after removal of the intest ine. Longi- 

 section. Zeiss oc. 3, ob. D. 



Fig. 21. Lateral anal oj^ening is being formed. Metamorphosed ectoderm 

 ou the posterior side of the invagination is entering the coelom. Tlie metamor- 

 phosed cells on the anterior side of the invagination are on the periphery of a 

 metamorphosed ai'ea which lies beneath the intestine and is sho^vii in the figure 22. 

 Longiscction of body. Zeiss oc. 3, ob. D. 



Fig. 22. Metamorphosed area of the ectoderm beneath the piano of section 

 shüwn in figure 21. Zeiss oc. 3, ob. D. 



Fig. 23. Deep infolding of the body wall at the posterior end of the body. 

 Metamorphosed cells and neoblasts on one side of the infolding. Zeiss oc. 3, ob. D. 



Fig. 24. Lwmhricus. Longisection of intestineless tongue of regenerated 

 tissue at the anterior end of the body. Photograph. 



Fig. 25. Disintegration of the old mesoderm at the anterior end of the body 

 preparatory to forming the mesoderm in the regenerated portion. Longisection. 

 Zeiss oc. 2, 2 mm oil imm. 



Fig. 26. A more advanced stage in the formation of the mesoderm at the 

 anterior end of the body. Longisection. Zeiss oc. 2, 2 mm oil imm. 



Fig. 27. The process of mesoderm formation at the anterior end of the body 

 almost completed. Longisection. Zeiss oc. 2, 2 mm oil imm. 



