CHEMICAL CONTROL OF RHEOTAXIS IN ASELLUS 



W. C. ALLEE 



Marine Biological Laboratory and Lake Forest College^ 



TEN FIGURES 



CONTENTS 



• I. Earlier work and methods 163 



II. Electrolytes 165 



1. Chlorine salts of alkali metals 165 



2. Different anions with cation potassium 171 



3. Chlorine salts of alkali earths 173 



4. Antagonisms 175 



5. Acids (H ions) 177 



6. Alkalies (OH ions) 180 



7. Distilled water 181 



III. Non-electrolytes 183 



1. Cane sugar 184 



IV. Metabolism and rheotaxis 186 



1. Does resistance to sodium cyanide measure the metabolic rate of 



Asellus? 186 



2. Effect of potassium chloride 188 



2. Effect of calcium chloride 189 



4. Effect of cane sugar 193 



V. Summary 195 



VI. Literature cited 197 



I. EARLIER WORK AND METHODS 



Certain conditions known to affect the metabolism of ani- 

 mals are known regularly to affect the rheotactic reactions of 

 the isopod Asellus communis Say. Lowered oxygen tension, 

 chloretone, potassium cyanide, lowered temperature, suddenly 

 increased temperature, increased carbon dioxide tension, and 



^ The experiments upon which this paper is based were carried on at Woods 

 Hole during the summers of 1913, '14, and '15. During this time 1003 individual 

 isopods were tested in a total of 13,245 minute reaction periods. I am indebted 

 directly and indirectly to many people with whom I have talked during the prog- 

 ress of the work, particularly to Dr. F. B. CofRn, for aid with certain phases of 

 the chemistry of the problem. 



163 



THE JOURNAL OF EXPERIMENTAL ZOOLOCJY, VOL. 21. NO. 2 

 .VCGUST, 1916 



