77") 



Bulletin 



Illinois State Laboratory 



Natural History 



Urbana, Illinois, U. S. A. 



STEPHEN A. FORBES, Ph.D., LL.D., 

 Director 



Vol. XL May, 1918 Articles VIII-X. 



ART. VIII. THE REACTIONS AND RESISTANCE OF FISHES TO 

 CARBON dioxide AND CARBON MONOXIDE 



BY 



Morris M. Wells, Ph.D. 



ART. IX. EQUIPMENT FOR MAINTAINING A FLOW OF OXYGEN- 

 FREE WATER, AND FOR CONTROLLING GAS CONTENT 



BY 

 Victor E. Shelford, Ph.D. 



ART. X. A COLLECTING BOTTLE ESPECIALLY .VDAPTED FOR THE QUAN- 

 TITATIVE AND QUALITATIVE DETERMINATION OF DISSOLVED 

 GASES, PARTICULARLY VERY SMALL QUANTITIES OF OXYGEN 



BY 



Edwin B. Powers, ]\I. A. 



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