Bulletin 



Illinois State Laboratory 



Natural History 



Urbana, Illinois, U. S. A. 



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



Director 



Vol. XL May, 1918 Articles VHI-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 ADAPTED FOR THE QUAN- 

 TITATIVE AND QUALITATR^ DETERMIN.A.TION OF DISSOLVED 

 GASES, PARTICULARLY VERY SMALL QUANTITIES OF OXYGEN 



BY 



Edwix B. Powers, M. A. 



