34. 



•edittK, 1* not correlated with a high rate of regenentlon. Both the relative 



decrease of carbon dioxide production In acid* aui Ibi relative increase of 

 osrbon dioxide production in bases increase as the size of the tadpoles decrease. 

 This 1* »ugs»otiv* of ■ correlation bot»een the of foot of acids and bases and 

 the area of tM tiinole. The relative deereate in regeneration of tadpoles 

 dus ie aoida and basse appeare to be independent of eiae, escactin$ in concen- 

 trations which are soon fatal to the entailer ones. 



The probability is suggested that hydrogen ion concentration, 

 insufficient oxy^et-, low temperatures and toxic substances affect devolopewnt, 

 regeneration, oxygen metabolism, and duration of life, according to the earns 

 laws, although the relative effeote of any given environmental factor upon the 

 variom functions of the organism Jiffsr, ami although the relative effects 

 of the same environmental factor nay differ in animals of different else* 



This work was done In the Zoological Laboratory of the University 

 of Illinois, unler the 'ireotion of Dr. V. I. Shelf ord, to whoa, the writer ie 

 Indebted for n<%aj courtesies a:;.' valuable suggestions. The writer ie also 

 Indebted to Dr. Charles Zeleny for suggestions concerning the methods used in 

 the work on regeneration, end to Mr. F. D. Powers for many ueeful suggestions 

 concerning the details of the work and the interpretation of dot*. 



