Carbon Monoxide in the Pneumatocyst of Nereocystis* 



Seth C. Langdon, 

 Department of Chemistry, University of Washington, Seattle. 



The gas content of the floats which buoy up certain marine algae 

 have been subjected to analysis by Rosanoff (7), Wille (H), and Lucas (5), 

 who report an oxygen nitrogen mixture with composition varying from 

 that of air, depending upon the condition. 



Zeller and Neikirk (12) in 1914, examined the gas contained in the 

 large Pacific Coast kelp Nereocystis luetkeana and reported carbon diox- 

 ide as well as nitrogen. Samples collected in the early morning were 

 high in carbon dioxide and low in oxygen and the reverse was true for 

 samples collected at evening. A summary of their results is given in 

 table 1. The author has added the difference column showing the per cent 



Table 1. Summary of results by Zeller and Neikirk, with N column added. 



Average Average per Difference Number of 

 per cent cent carbon called determin- 



oxygen dioxide nitrogen ations 



Gas collected 3-4 A. M 10.96 2.503 87.537% 9 



Gas collected 3-4 P. M 12.304 0.293 87.403% 6 



of unabsorbed gas which was assumed to be nitrogen and which is prac- 

 tically the same in each case. Among the individual measurements given 

 by Zeller and Neikirk the deviation from the mean values for oxygen and 

 carbon dioxide are slight. Figures for fifteen analyses are given and no 

 statement is made as to how extensively the investigations were carried 

 out. Zeller and Neikirk used a Hempel apparatus consisting of a modi- 

 fied Winkler gas burette, a simple absorption pipette for carbon dioxide, 

 and a double absorption pipette for oxygen. They arrived at the con- 

 clusion that "the pneumatocyst of Nereocystis is not merely a means by 

 which the plant is buoyed up to the light, but it serves as a reservoir in 

 the gas exchange of the metabolic processes." 



At the suggestion of Dr. T. C. Frye, Director of the Puget Sound 

 Marine Station, the author undertook to check these results. More re- 

 fined methods of analysis were used and numerous measurements were 

 made, extending over the period from June 10th to August 20th, 1916, but 

 the results failed to check the work of Zeller and Nekirk. This is brought 



♦The subject matter of this article is to appear in the January, 1917, num- 

 ber of the Journal of the American Chemical Society. 



(237) 



