21. 

 affect* on* of tfceae funotiona will. If continued for •> sufficient time nnd 

 intensity affect ?*11 of thi function* eiitil^rly and in the euae direction la 

 eugge*tsd by the similarity of the curves. The only apparsnt exception Is the 

 increase in C0 2 production, due to conoontr.it ions of bases which o *u»oJ retarda- 

 tion of regeneration, an) issth. Mo«evor, an haa *e*n pointed out, thia 



inore ao in oxygon astabolisft a<iy b« regarded as a destructive metabolism and 

 coap*r*blo to death rather than to growth or devolopswnt. 



Figures 26, 27 and 38 are curves giving the tine neeasuir? to 

 complete the regeneration of various p^roentagaa of the amounts removed in 

 KKOg, HBr and H^BO^ respect ivsly. A comparison of these curves with the curvsa 



for regeneration in bases of vari>.a« percentages of the amounts removed (Figures 

 12, 14, 16 ind 20) shows that while in sons cases (Figures 14 and 20) the regen- 

 eration of tadpolea In the higher concentrations of base* scorns to follow no 

 definite plan, that in gsnornl the curves are similar. In any given series 

 all of the curves of regeneration - which represent different stages in regener- 

 ation of the sans animals * are eonfconl. This shows thst while the rite of 

 regeneration at different stages la different, the p*r cent of retardation as 

 oomparad to th<» normal, due to tha acid or base,, la the asms for all stages, or 

 that for each concentration tha rei.tive velocities for the different stages 

 are prastically the seas. This is similar to the findings of Krogh (1914a) 

 in his work on the development of frogs' eggs at various tempo rat urea. 



Ctrbon Dioxide Production and Regeneration in Acids. 



The next eerlea (Fxrsriments 13 and 14) was undertaken to see 

 whether any correlation could be found between the regeneration and oarbon 

 dioxide production in acids. Ten sets of four tadpoles each of as nearly the 

 satis also as possible were use). The normal serbon dioxide production in 



distillsd vatsr for n period of throe days was determined after a two-day fast 



