PLATE 2 



EXPLANATION OF FIGURES 



7 A transverse section of graft LN 79, illustrating amorphic regeneration. 

 Only grafted tissue is shown. The notochord (n) is in two parts, the larger 

 being the old notochord and the smaller being the regenerated notochord. The 

 nerve cord is seen just beneath the notochord. Due to the irregularity of the 

 proliferated tissue, there are several spaces lined by epidermis, all of which open 

 to the outside, however. X 34. 



8 Transverse section of graft LB 10 three days after the operation. Beneath 

 the graft is seen the integument of the host {hi) with many blood cells in the der- 

 mis. Blood cells have also penetrated the notochord (n) of the graft. Subse- 

 quent behavior of such autotransplants results in the lining of the space between 

 graft and host by epidermis, with an opening to the outside somewhere. X 51i. 



9 Transverse section of graft LO 2 five weeks after the operation. It will 

 be noticed that the dorsal side of the graft (lower edge in figure) has become con- 

 tinuous with the skin of the host, due to establishment of union distally. The 

 other side has united proximally. X 38. 



10 Transverse section of graft LO 2 near the posterior edge, showing the 

 point of union on the dorsal side. The epidermis on the under side of the graft 

 and the epidermis of the host, covered by the graft, have become continuous, 

 thus lining the cavity. X 45. 



11 Tangential section, nearly longitudinal, of graft LN 78, showing boundary 

 between old grafted tissue and the new proliferated tissue, n, notochord of old 

 tissue; rn, regenerated notochord; nc, regenerated nerve cord. X 97|. 



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