374 WILLIAM H. COLE 



excepting LN 62 and 88, with or without absorption history, 

 began to proHferate. The formation of new tissue by the graft 

 was never observed to occur during the adjustment period. It 

 is assumed that a profound change takes place in the tissues of 

 the graft which makes them incapable of further adjustment and 

 initiates growth. Previous to such a change the connection of 

 the blood vessels of the graft to those of the host has been com- 

 pleted. It is likely, then, that with the normal blood supply 

 restored, the transplant is able to form new tissue. This new 

 activity, recognized by an increase in size of the graft and directly 

 opposed to absorption seen in the second period, predominates 

 during the third period. No further adjustment ever takes 

 place. It is suggested by this fact that the absorption process in 

 a certain part of the graft may be aided by a poorer blood supply 

 in that region than in other regions. 



The originally anterior and posterior ends of the giaft show 

 new tissue before the sides, and the amount produced at the ends 

 is much greater than that at the sides. In many grafts, however, 

 the proliferation was distributed irregularly over the surface, 

 constituting amorphic regeneration. The limits of the old tissue 

 are easily distinguishable from the new by the larger number of 

 melanophores in the former — a condition which persists for 

 months. 



When growth begins it proceeds rapidly for a time, and then 

 almost suddenly ceases. The following abbreviated notes from 

 the records of LN 79 illustrate the history of a typical case of 

 proliferation : 



Oct. 4, 1920. Auto-tail-graft over right eye in original orientation. 



Oct. 5. Complete union along all edges. During the next two 

 weeks no noticeable changes occurred. 



Oct. 20. Outgrowth along posterior edge of the graft. 



Oct. 22. Very slight proliferation along the two sides. Noticeable 

 increase in the amount of new tissue at posterior end. 



Oct. 24. Posterior outgrowth is distinctly triangular in shape. No 

 increase in lateral growth. 



Oct. 30. Posterior outgrowth appears like a normally regenerated 

 tail tip. 



Nov. 3. No further increase in proliferation. 



Nov. 17. No changes. 



Jan. 9, 1921. No changes; animal killed and graft fixed for sectioning. 



