THE ABSORPTION OF NUTRIMENT FROM 

 SOLUTION BY FRESHWATER MUSSELS' 



E. P. CHURCHILL, JR. 



From the United States Biological Station, Fairport, Iowa, and the Zoological 

 Laboratory of the Johns Hopkins University 



THIRTY FIGURES (TWO PLATES ) 



CONTENTS 



Introduction 403 



Materials and methods 407 



Mussels and water used 407 



Fat 407 



Protein 408 



Starch 408 



Observations 409 



Fat 409 



Unstained soap solutions 409 



Stained soap solutions 410 



Direct absorption by cells of outer body walls 411 



Protein 411 



Starvation method 411 



Comparison of granules in the cells 413 



Tests for specific stains 414 



Janus green method 416 



Direct absorption by cells of outer body walls 417 



Starch 418 



Iodine test 418 



Solutions stained with iodine 419 



Behavior of the corpuscles 419 



Summary and discussion '. 420 



Literature 424 



INTRODUCTION 



In 1914 the author began a series of investigations upon 

 fresh-water mussels designed to ascertain whether or not there 

 could be found any direct proof, especially of a histological 

 nature, of the correctness of Putter's theory that animals living 



^ Published by permission of the Commissioner of Fisheries. 



403 



