Sonif l'hcnometn nf Regencnitioii in IjiiiiinKlrilus aiid iclilofl Forms. 419 



figiirc is givcMi in terms ul Ihr (n iil.ii miuI olijt'ftivc iisetl. Tlic tigiires Iwivü l)een 

 leduced two tliirds. 



Plate XII-XIV. 



Fiti. 1. liulicatcs conditions almost immcdiatcly after tlie inicstinc has 

 beeil dnnvn out of the posterior and of the body. Zeiss oc. 3, ob. D. 



Fig. 2. This figure serves the dimblc purpose of showing the posterior end 

 of the body after tlie ectoderin has grown ovcr the wound and also tlie apjiearancc 

 of tlie ectoderin in the scar region when no ncobhists arc ncar it. Zeiss oc. 3, ob. D. 



Flu'. :>. Pliotograph of the Strand which is foi'med at the posterior end of 

 body after tlie intest ine has been removed. Zeiss oc. 0, ob. 0. 



Fig. 4. Photograph of a diagonal Strand extending from the posterior end 

 of the body to a more anterior point in the sidc of the body wall. Zeiss oc. 0, ob. 0. 



Fig. 5. The posterior end of an intest ine which was cut off at the lOth 

 soniite but did not rcgenerate. Zeiss oc. 3. ob. D. 



Fig. 6. The beginning of regeneration at the posterior end of an intestine. 

 A Strand of muscle fibers is also sho\vn projecting into the coelom. Zeiss oc 3, 

 ol). D. 



Fig. 7. A niore advanced stagc in the regeneration of the intestine. The 

 regeneration of the intestinal niusculature is also indicated and a pseudoprocto- 

 daeum is likewise shown. Zeiss oc. 3, ob. D. 



Fig. 8. Shows the migration of the chlorogogue to the rcgenerated portion 

 of the intestine. Only one side of the body has been drawn. Zeiss oc. 3, ob. U. 



Fig. 9. Two neoblasts with amoeboid pseudopodia. Zeiss oc. 3, ob. 2 mm 

 oil Immersion. 



Fig. 10. Xeoblasts migrating along the nerve to the wound at the posterior 

 end of the body. The arrow shows the direction of the migration. Zeiss oc. 3, 

 ob. D. 



Fig. 11. Neoblast in „resting*- condition attached to a septum. 



Fig. 12. A group of neoblasts at the posterior end of the nerve cord before 

 septa have begun to form. Tlie ectoderm opposite the neoblasts is just beginning 

 to change its character. Zeiss oc. 2, ob. 2mm oil imra. 



Fig. 13. Shows the great similarity between the neoblasts and the meta- 

 morphosed ectoderm cells. The secticm is taken in such a plane (a short distance 

 to one side of the median longitucUnal axis of the body) as to make it appear as 

 tho the ectoderm cells were entering the coelom. Zeiss oc. 2, 2mm oil imm. 



Fig. 14. Illustrates the formation of septa from the neoblasts. The smaller, 

 bivsally situated neoblasts are forming longitudinal muscle. Opposite the neoblasts 

 are some ectoderm cells which will iater form circular muscle. Farther toward 

 the anterior end about opposite the longest septum the circular muscle fibers are 

 beginning to form at the bases of the ectoderm cells. Zeiss oc. 2, 2mm oil imm. 



Fig. 15. Gross section of the body taken near the posterior end. Shows 

 similarity between metamorphosed ectoderm cells and the neoblasts. Along 

 the sides the ectoderm cells are dividing to form circular muscle. Zeiss oc. 2, 

 ob. 2 mm oil imm. 



Fig. 16. Gross section of body taken farther forward thau was fig. 15. 

 Circular muscle cells of ectoderm in position but fibrils not yet formed. Zeiss 

 oc. 2, ob. 2 mm oil imm. 



