Physiology of Regeneration 615 
ated than in the control worms, which were kept in pure sea- 
water. 
I performed the same kind of an experiment in the summer of 
1908 with the same result. As will be seen from Table IX, 
the old pieces were practically of the same length in the control 
and in the experiment. But there was a considerable difference 
in the number of segments regenerated from worms that had been 
fed and those that had not been fed. 
TABLE IX 
AUGUST I2-AUGUST 22, 1908 | NUMBER OF SEGMENTS AVERAGE 
(ear e| [ous Peal keeel ite ae si} | 
old ts | 151818 619) | 17. 
Worms not a anes mulee eines Rela | | gee: 
if new segments) 4 4 4 4) 4! 5) 5/ 5) 5| 6 | 4.6 
| ee | | | al Wea Pes ap ae (a | et el gd eS 
ea a a Gat i G7 
i old segments 23/1513.21 1720161717 181617 17\191617/202019151718, 21.3 
Worms fed Daa ip | | Nee | 
f eo fe Pi Pa Pe ld A 6.4 
wa a | | | | | i | i | 1 | 
TABLE X 
AUGUST 22-AuGuSsT 28, 1908 | NUMBER OF SEGMENTS AVERAGE 
Worms not fed | new segments | 4 | 4 | ES aes | 6 8 | | | 5:3 
Worms fed | new segments (6 6 eT at7: | 81919 | 9\9 | 9| 9 | 10 19 ai 8.4 
: Vamos es | 
From this table we find that at the end of ten days after the 
operation the number of regenerated segments of the control 
worms varied from 4 to 6, while that of the well-fed worms varied 
from 4 to 8. A similar difference was found with the same lots 
at the close of sixteen days (see Table X), when the number of 
new segments varied in the control from 4 to 8, and in the experi- 
ment from 6 to 10.5 The mere numbers do not give a perfect 
presentation of these differences, which are by far more striking 
when the animals themselves are compared. From exact meas- 
5 Unfortunately some of the control worms died before the end of the experiment. This accounts 
for the fact that the number of specimens in the control is smaller than in the experiment. In view 
of this circumstance I wish to point out that in 1907 there were twice as many specimens in the con- 
trol (Table I) as in the experiment (Table VIII). The results, however, are similar in both cases. 
