16 



Miss D. J. Lloyd. Influence of Osmotic 



The slight degree to which the reduction processes are carried is reflected in 

 the external form of these pieces, which only suffers very slight changes 

 during the time (e/. figs. 5 and 15). 



Fig. 15. — Stages of Eegeneration in 100 c.c. sea-water + 20 c.c. 2|M NaCl. 

 1. 10 days. 2. 14 days. 3. 28 days. 4. Side view of 3. 



Many sections were examined for mitotic figures, and a comparison was 

 made between the mitoses found in worms regulating in sea-water and in 

 water with a higher or lower osmotic pressure. Text-fig. 16 shows the type of 

 mitoses found. At osmotic pressures of 7'5 and 33 atmospheres the mitoses 

 appear to be a little irregular, but in all cases mitotic figures are so rare that 

 it would not be justifiable to ascribe a principal role in the failure to 

 regenerate, to any such irregularities. 



2 2 3 i? 



20 



- Fig. 16. — Mitotic Figures from the Parenchyma Cells. 



1-4. From tissue regenerating in sea-water. 5-7. From tissue regenerating in 100 c.c. 

 distilled water-)- 50 c.c. sea-water. 8-12. From tissue regenerating in 100 c.c. sea- 

 water +20 c.c. 24-M NaCl. 



