iQ2o] LANGDON &• GA1 LEY— CARBON MONOXIDE 239 



3. Kelp plants, in which the gas normally present within 

 the floater is replaced by air, form several per cent of carbon 

 monoxide within a few days. 



4. The formation of carbon monoxide takes place only when 

 oxygen is present as one of the gases within the floater. No car- 

 bon monoxide is formed when the floater is filled with nitrogen or 

 hydrogen. 



5. Light does not affect the rate of formation of carbon mon- 

 oxide. 



6. The gas obtained from the cavities of various other plants 

 failed to show a similar occurrence of free carbon monoxide. 



7. The percentage of free carbon monoxide which occurs in 

 the floater of Nereocystis Luetkeana is considered to be a respiration 

 product for the following reasons. It forms only when oxygen is 

 present within the floater; it forms as readily in the dark as in 

 the light; it is not formed by enzyme or fermentation process 

 when the substance of the plant undergoes autolysis and decay; 

 and it is not formed in killed plants. 



In conclusion, the authors wish to acknowledge the many 

 courtesies extended to them by Dr. T. C. Frye, Director of the 

 Puget Sound Marine Station. 



Evanston, III. 



