284 



LEONARD P. SAYLES. 



TABLE IV. 



4 DAYS OF REGENERATION. 



TABLE V. 



5 DAYS OF REGENERATION. 



TABLE VI. 



6 DAYS OF REGENERATION. 



In making these counts it is necessary to adopt some criterion 

 for double nucleoli. These figures, therefore, are for cases where 

 a nucleus contains two nucleoli in approximately the same focal 

 plane of the microscope. In order that the personal equation 

 involved in making the counts may be made as negligible as 

 possible, instances of dumbbell-shaped or elongated nucleoli are 

 not included. Records are not given for segments beyond the 

 fourteenth from the wound since but 2 or 3 double nucleoli per 

 segment, the number ordinarily found in an uninjured worm, 

 are to be found in these. For mitotic figures all stages from the 

 appearance of the chromosomes in the prophase to the late 

 telophase are included. 



As already mentioned, the gut cells of these worms ordinarily 

 have nucleoli of considerable size, averaging about i /x in diameter, 

 and the oval nuclei measure on the average about 4 x 7 p.. With 

 the onset of regeneration an increase in the size of the nuclei 

 and nucleoli begins, though it is comparatively slight in the 

 former case. 



