630 STUDIES IN GENERAL PHYSIOLOGY 
bottom of the dish. All these processes may occur in less 
than a day, and can be observed directly with a lens. I will 
try to give a description of these phenomena with the aid of 
camera drawings I made while observing them. Fig. 152 
shows the condition of a 
Campanularia stem that 
had been put on the bot- 
tom of a watchglass the 
FIG, 152 previous day. Originally 
it had five perfectly de- 
veloped polyps. Only 
two of these are left (4 and 5); the three others 
(1, 2, and 8) have disappeared. At the lower 
t end, a, of the original stem a new stolon, a b, 
has grown out. What had become of the three polyps 
that had disappeared? I watched them very closely and 
found that they were transformed into a shapeless mass 
and withdrawn into the stem. I will describe this process 
of transformation of polyps into the material of the stem 
more minutely with the help of Figs. 153, 154, 155. These 
are not taken from the same stem, but as the process 
occurs almost always in the same form, this makes no 
material difference. 
The transformation of a polyp into the less differentiated 
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