Effect of Successive Removal upon Regeneration 511 
3 In one group of experiments the effect of successive removal 
as a whole was studied. In the other group the local effect only 
was determined. 
4 In the larval salamander the experiment was well controlled 
and showed in each set an advantage in favor of the later regener- 
ations. 
5 In Cassiopea the number of individuals was insufficient to 
make the result absolutely certain, but each of the later regenera- 
tions was distinctly in advance of the first. 
6 In crayfish and gulf-weed crabs there was no change with 
successive removals. Both animals furnish a special difficulty in 
the shape of the molting habit, but this was controlled as perfectly 
as possible. 
7 In the case of the gulf-weed shrimp Palzmon tenuicornis an 
important factor, the age factor, was not eliminated, and while in 
single individuals there was a decrease in rate of regeneration with 
successive injury, this may have been due to normal age decrease. 
The number of individuals also was insufficient. 
8 The local effect was studied in the chelz of the Wood’s Holl 
shrimp, Palamonetes vulgaris Stimp, and in the margin of the 
disk in Cassiopea xamachana. 
g The chelz of Palamonetes showed a slight advantage of the 
first regeneration over the second, but since it amounted to only 
1.4 per cent of the length regenerated it. may not be significant. 
10 The margin of the disk in Cassiopea xamachana ‘showed 
an advantage of the second regeneration over the first, but not as 
pronounced a one as in the cases in which the whole constitutional 
effect was in question. 
BIBLIOGRAPHY 
Davenport, C. B. ’99—Experimental Morphology, vol. ii. 
Driescu, Hans ’97—Studien tiber das Regulationsvermégen der Organismen, I. 
Von den regulativen Wachstums- und Differenzirungs-fahigkeiten 
der Tubularia. Roux’s Archiv, Bd. v. Ht. 3. 
Dursin, M. L. ’og—An Analysis of the Rate of Regeneration throughout the 
Regenerative Process. Journal of Exp. Zodl., vol, vii, no, 3. 
