AUTHOR S ABSTRACT OF THIS PAPER ISSUED BY 

 THE BIBLIOGRAPHIC SERVICE, MARCH 14, IQ2I. 



STUDIES OF THE BIOLOGY OF FRESHWATER 



MUSSELS. 1 



EXPERIMENTAL STUDIES OF THE FOOD RELATIONS OF CERTAIN 



UNIONIDJE. 



WILLIAM RAY ALLEN. 



CONTENTS. 



PAGE. 



1. Introduction 210 



2. Constancy of the feeding activity 211 



(a) The feeding posture 212 



(fe) Hunger and the degree of digestion 213 



3. The utilization of nannoplankton and megaloplankton 215 



(a) Experiments in selective feeding , 216 



(b) The feeding of sewage 220 



(c) The feeding of infusions 221 



4. The physiology of the crystalline style 223 



(a) Recent studies 223 



(b) The feeding of specific substances 226 



(c) Forced feeding 229 



(d) The effect of temperature on style renewal 229 



5. The mechanism of ingestion 232 



(a) The role of the labial palps 234 



(fr) The gills as an assorting mechanism 235 



(c) The marly incrustation of the shell 238 



6. Summary and conclusions 238 



i. INTRODUCTION. 



The writer, while a member of the Indiana University Biolog- 

 ical Station at Winona Lake, Indiana, devoted several summers 

 to ecological studies of the freshwater mussels. The work was 

 done under the direction of Dr. Will Scott, and formed a part 

 of his general limnological program. A first paper on the feed- 

 ing habits of the Unionidse appeared in 1914. The present paper 

 has expanded the former through the use of experimental 



1 Contribution from the Zoological Laboratory of Indiana University No. 

 174; submitted as a partial fulfillment of the requirements for the degree 

 Doctor of Philosophy. 



2IO 



