Vol. XXXI. November, igi6. No. 5 



BIOLOGICAL BULLETIN 



ON THE BEHAVIOR OF AMEBA TOWARD FRAGMENTS 

 OF GLASS AND CARBON AND OTHER INDIGESTIBLE 

 SUBSTANCES, AND TOWARD SOME VERY SOLUBLE 

 SUBSTANCES. 



A. A. SCHAEFFER, 

 ZOOLOGICAL LABORATORY, UNIVERSITY OF TENNESSEE. 



CONTENTS. 



Introduction 303 



Reactions to Chemically Insoluble Indigestible Substances 304 



Carbon 304 



Glass 308 



Graphite 311 



Silicic Acid 312 



Hematin 312 



Indigotin 313 



Cholesterin 313 



Starch grains from Arrowroot 313 



Lead Oxide 314 



Reactions to Very Soluble Digestible Substances 315 



Tyrosin 315 



Gelatin 319 



Arrowroot Starch Paste 319 



Reactions to Substances in Solution 320 



Peptone 320 



Egg Albumin 322 



Tyrosin 323 



Carmine 324 



Summary 325 



Bibliography 326 



Explanation of Plates 328 



Table of Abbreviations 328 



INTRODUCTION. 



The experiments recorded in this paper were carried out in 

 order to come a step closer to understanding the nature of the 

 stimulus which, emanating from an insoluble particle such as 

 ovalbumin, zein, or lactalbumin, results in an ameba moving 



303 



