496 



MINNA E. JEWELL 



If decrease in CO2 production, weight, and area be compared, 

 using the large size as 100 per cent, the decrease in CO2 production 

 appears to be fairly well correlated with area. This evidence is, 

 however, offset by the fact that the daily CO2 production per 

 gram of tadpole is practically the same for all three sets as though 

 the lowered oxygen metabolism produced by the acid had bal- 

 anced the shortage of oxygen in the experimental jars of the larger 

 tadpoles mentioned above. 



Another series was attempted in which the error due to the 

 large tadpoles exhausting the air in their jars was avoided by 

 putting the same weight rather than the same number of tadpoles 

 in each jar; thus a jar might contain one large tadpole, three 

 medium-sized tadpoles, or six small ones. Four sets of each 

 size were weighed and measured. The COo production in dis- 

 illed water, which was then determined for each set for six 

 successive days, varied from 5.65 to 6.45 cc. 0.01 N H2CO3 per 

 gram per day. This variation bore no relation to size, as the 

 extremes were both found in the largest size. The CO2 produc- 

 tion of the smallest size varied from 5.7 to 6.2 cc. per gram per 

 day. The average CO2 production per gram per day was for 

 the largest size 6.13 cc; for the second size 6.04 cc, and for the 

 small size 5.96 cc. In view of the wide variation in CO2 produc- 

 tion between different sets of tadpoles of the same size, the differ- 

 ences in these numbers are probably not significant. 



After the determination of normal CO2 production in distilled 

 water, one set of each size was continued in distilled water as a 

 control, and one set of each size was put into 0.0005 N KOH, 

 Ca(0H)2, and H2SO4, and the COo production determined for 

 four successive days. Due to the early death of some of the 



