172 
Journal of the Mitchell Society [. December 
and the larvae are gradually converted into a flattened cake. 
The larger cakes thus made measured four by three millime- 
ters. The body of such a cake is a continuous flattened mass 
in which there is no indication of the component larvae, but 
the rounded ends of the larvae that have last fused with the 
general mass remain for a time distinguishable. Owing to 
their blue coloration the ends of the larvae may be recognized 
in these and the other compound masses even after the outline 
of the larva has been completely lost. 
As already stated the smaller compound masses metamor- 
phose without difficulty. The coalesced larvae may be made 
to attach to cover glasses, slides, etc. Larger masses com- 
posed of about twenty larvae underwent a partial metamor- 
phosis. Such masses were laid upon bolting cloth to which 
they readily attached. The larges masses were hung in 
small bolting cloth bags in a live box. Whether owing to 
bad handling or more probably to some inherent difficulty, 
they did not metamorphose but soon died. 
The ease with which larvae of the same species may be 
made to fuse together suggests that larvae of different species 
might likewise be induced to coalesce. Some experiments 
along this line could not fail to be of interest. 
IV 
In the tendency to fuse with the production of a plasmo- 
dium, the dissociated cells of sponges resemble the amoebo- 
cytes (amoebulae) of the mycetozoa and Protomyxa. The 
regenerative power of the plasmodium has an interest both 
theoretical and economic in itself. But it is the tendency to 
fuse displayed by the cells that have been forcibly broken 
apart, which constitutes the fact of most general physiolog- 
ical importance. Discarding for the moment the word “cell” 
and speaking of the protoplasm of a species as a specific sub- 
stance, the phenomena may be restated to advantage in the 
following way. 
A mass of sponge protoplasm in the unspecialized state 
typically exhibits pseudopodial activities at the surface. In 
