OCT 1 1357 BULLETIN 



Illinois ^tate Laboratory 



NATURAL HISTORY. 



Urbana, Illinois 



VOLUME V. 



ARTICLE I.—PLAiYKTON STUDIES. /. METHODS AiVD 

 APPARATUS IN USE IN PLANKTON INVESTIGA- 

 TIONS AT THE BIOLOGICAL EXPERIMENT STA- 

 TION OF THE UNIVERSITY OF ILLINOIS. 



By C. a. KOFOID, Ph. D. 



Illinois State Laboratory of Natural History, 



IKBANA, ILLINOIS. 



■'1897. 



