THE EFFECT OF ALKALIES ON THE OXYGEN COX- 

 SUMPTION AND SUSCEPTIBILITY OF PLAN ARIA 

 DOROTOCEPHALA.^ 



LOUISE A. ANDERSON, 

 HULL ZOOLOGICAL LABORATORY, UNIVERSITY OF CHICAGO. 



I. 



INTRODUCTION. 



Considerable work has been done in this laboratory by Child 

 and his students on the effect of chemical and physical agents on 

 the modification of development and regeneration of organisms. 

 For the interpretation of these results it is desirable that the ac- 

 tion of the more commonly used chemicals on the rate of some 

 metabolic process, such as respiration, be determined directly. 

 Some work has already been accomplished along these lines, the 

 effects of several substances on the rate of oxygen consumption 

 having been tested: cyanides (Hyman, '190), anesthetics (Bu- 

 chanan, '22). caffein (Hinrichs, '24), and acids (Hyman, '25). 

 The present paper is a contribution to this line of work and con- 

 sists mainly of a study of the action of alkalies on the rate of 

 oxygen consumption of Planaria dorotocephala. Hyman ('25) 

 has already shown that acidification of natural water decreases the 

 rate of oxygen consumption of Planaria. The question of the 

 effect of increased alkalinity of natural water seemed of interest. 



A number of investigations are available on the effect of in- 

 creased alkalinity on various biological processes, such as activity, 

 growth and development, and respiratory rate. Loeb ('98) found 

 that the rate of embryonic development of Arbacia and Fundulus 

 is accelerated in slightly alkaline solutions. Moore, Roaf, and 

 "\Yhitley ('05) also noted that bases in low concentrations favor 

 growth and cell division in the fertilized eggs of Echinus cscitlcn- 

 tus; but "YVhitley ('05) failed to obtain any accelerating effect of 



1 Accepted as a thesis for the degree of Master of Science in the department of 

 zoology of the University of Chicago. 



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