Fig. 1 Graph showing the regeneration of large tadpoles in increasing con- 

 centrations of KOH. Each line represents the regeneration of one tadpole. 

 Dotted line, control; ordinate, per cent regenerated; abscissa, time in days; nu7n- 

 bers at ends of curves, cc. O.OIN KOH in 200 cc. of solution. Note decrease in rate 

 of regeneration and total amount regenerated in higher concentrations. Com- 

 pare with figure 2 which represents regeneration of small tadpoles in correspond- 

 ing solutions. From data of table 1. 



Fig. 2 Graph showing the regeneration of small tadpoles in increasing con- 

 centrations of KOH. Plotted as figure 1. Dotted line, control. A comparison 

 of this figure with figure 1 shows the relatively more rapid and more complete 

 regeneration characteristic of smaller tadpoles. Note also that except in case 

 of the small tadpoles in 20 cc. of KOH, which died without regeneration, the 

 relative effect of the higher concentrations is about the same for both sizes. 

 From data of table 2. 



Fig. 3 Graph showing daily GO2 production of tadpoles in increasing con- 

 centrations of KOH. Ordinate, concentration as cc. O.OIN KOH in 400 cc. of 

 solution; abscissa, CO2 produced as cc. O.OIN H2CO3; curve 1, average GO2 pro- 

 duction for twenty-four days; curve 2, CO2 production of the first day. A com- 

 parison with figures 1 and 2 shows that the same concentrations of KOH which 

 increase CO2 production inhibit regeneration. From data of table 3. 



Fig. 4 Graph showing the oxygen consumption of fertilized eggs of Strongy- 

 locentrotus purpuratus in increasing concentrations of NaOH. Ordinate, con- 

 centration as cc. O.IN NaOH in 50 cc. of the solution; abscissa, coeflBcient of 

 oxygen consumed as compared to neutral controls. Drawn from the data of 

 Loeb and Wasteneys ('13 b). This curve, which represents oxygen consumption, 

 is essentially similar to figure 3 which represents CO2 production in a basic 

 medium. 



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