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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 



a-.. 



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 3) have disappeared. At the lower 

 end, a, of the original stem a new stolon, a 6, 

 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 and withdrawn into the stem.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 



