HARRIET L. ROBBINS AND C. M. CHILD. 



a measure of physiological and particularly of respiratory con- 

 dition. 



CARBON DIOXIDE PRODUCTION AFTER REGENERATION. 



In these experiments stocks of pieces of the size of A, B, C, 

 Fig. I, were cut from animals 16 18 mm. and allowed to undergo 

 regeneration until the development of the new individuals was 

 essentially complete, usually about two weeks. From these 

 stocks the experimental lots were selected. These consisted 

 only of normal individuals, or in some cases where the number 

 of normal animals in the regenerated stock was not sufficient, 

 mostly of normal with a few teratophthalmic individuals (Child, 

 'na) added. Since the pieces undergoing regulatory develop- 

 ment cannot feed until they attain an advanced stage, the animals 

 representing the condition before regulation, with which the 

 regenerated individuals are to be compared, are kept without 

 food for the same length of time as the pieces undergoing regener- 

 ation. Usually a stock of intact worms of the same size, 16-18 

 mm., as those from which the pieces were taken is isolated at 



TABLE II. 



A COMPARISON OF SMALL ANIMALS REGENERATED FROM PIECES WITH LARGE 

 ANIMALS THAT HAVE NOT RECENTLY UNDERGONE REGENERATION OR FISSION, 

 OF THE SAME SIZE AS THOSE FROM WHICH THE PIECES WERE TAKEN. BOTH 

 UNFED. DETERMINATIONS OF pH AT + 18 C. 



