666 JULIAN S. HUXLEY 
changes in the cells, changes which are partially restrained 
by the action of a narcotic like alcohol. 
It should perhaps be mentioned that not only oozoites which 
had lived some time in the circulation, but also those which had 
only just metamorphosed, could be induced to dedifferentiate. 
Larvae were allowed to fix on slides on July 28. After seven 
to nine days in the laboratory they showed the first signs of 
reduction. On the tenth day their water was changed, but 
without effect on the result, for on the eleventh and twelfth 
days all were markedly reduced. A sausage-shaped mass, 
sometimes showing a slight constriction between pharynx and 
abdomen, lay in a much-swollen, but healthy, test, which was 
usually attached to the substratum in the form of a flattened 
sphere. The remains of the test of the larval tail could be seen 
attached to one point of the main test. In some examples 
an interesting modification was observed—a small portion of 
test surrcunding the reduced zooid became constricted off 
from the main portion, which, though thus empty, remained 
healthy (‘Text-fig. 1, 8). 
In one or two specimens, detached, rounded masses of cells 
were to be seen outside the limits of the reduced zooid ; these 
were also occasionally seen in reduced blastozoites. I believe 
them to have been derived from the organism itself, and not 
to have been merely collections of cells of the test. Such 
collections were also seen, but never had the compact appear- 
ance of the first-mentioned masses. 
Swellings of the Test.—These have been already 
referred to. In connexien with experiments on dissociated 
sponges which were proceeding at the same time, it was decided 
to see whether portions of test were capable of re-organization 
or of regeneration in sea-water, or of growth in a nutrient 
solution. Accordingly a number of these ‘ test-bladders ’ 
were snipped off and isclated. After cuttmmg the pieces were 
always tern and quite flabby. Some were placed in sea-water. 
others in weak solutions of peptone made up either in tap- 
or sea-water. In all cases a marked reorganization had taken 
place within twenty-four hours. The wound was completely 
