Vol. XXIX. October, 1915. No. 4 



BIOLOGICAL BULLETIN 



REACTIONS AND RESISTANCE OF FISHES IN THEIR 



NATURAL ENVIRONMENT TO ACIDITY, 



ALKALINITY AND NEUTRALITY. 



MORRIS M. WELLS. 



PAGE. 



I. Introduction 221 



II. Apparatus and Methods 222 



A. Reaction Experiments 222 



B. Resistance Experiments 225 



III. The Water 225 



IV. Presentation of Data 231 



A . Reaction Experiments 231 



1. Reaction to Acids 231 



(a) To Carbonic Acid 231 



(b) To Sulfuric Acid 232 



(c) To Acidity in Distilled Water 234 



2. Reaction to Alkalies 235 



(a) In Neutral Water 235 



(b) In Strongly Acid Water 235 



3. Conclusions Drawn from the Reaction Experiments 239 



B. Resistance Experiments 239 



1. Resistance to Acids 239 



2. Resistance to Alkalies 240 



3. Resistance to Neutrality 240 



V. General Discussion 243 



VI. General Conclusions 254 



VII. Acknowledgments and Bibliography 254 



I. INTRODUCTION. 



The present paper is the first of a series that is to deal with 

 the relation of fishes to ions in the natural environments. It 

 is purposed to point out some of the close correlations which 

 exist between the physiology of fishes and their behavior, and 

 to present evidence concerning the importance of such corre- 

 lations in biological investigation in general. The data pre- 

 sented in the following pages deal with the reactions and re- 

 sistance of fresh water fishes to acidity, neutrality and alkalinity; 



221 



