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LEONARD P. SAYLES. 



with the result that the total number is not appreciably changed. 

 Table VII. gives the comparative abundance of double nucleoli 

 in the first five segments and in the other seven which are 

 apparently involved in the regenerative processes. 



The number of mitoses also decreases in the more distant 

 portion but in this case it is not compensated by an increase 

 near the wound so that the total number is less. The major 

 part of the activity of the gut in forming new tissue, therefore, 

 is now confined to a more restricted area. Table VIII. gives 

 data for mitoses corresponding to that given in Table VII. for 



double nucleoli. 



TABLE VIII. 



NUMBER OF MITOSES. 



The records for the fifth day are approximately the same as 

 those for the fourth. On the sixth the numbers both of double 

 nucleoli and of mitoses have decreased decidedly throughout the 

 entire region involved in regeneration. This decrease is most 

 marked, however, in the more distant segments. By the seventh 

 day the intestine of the old region has returned to approximately 

 its usual appearance in an uninjured worm. Only two or three 

 cases of mitosis are to be found and double nucleoli are little if 

 any more abundant than in intact animals. 



Beginning with the second or third day many cells in which the 

 nucleoli are small are present in the intestine of the old part. 

 These are probably the products of a recent mitotic division 

 during which the nucleolus has been lost. That the nucleoli of 

 these cells enlarge gradually is evidenced by the fact that the 

 number of such cells does not increase appreciably during further 

 regeneration. Similarly most of the cells in the newly formed 

 gut tissue of the regenerating bud have small nucleoli at first. 



