Micrometabolism of Nereocystis 



Joanne Karrer, 

 University of Washington, Seattle. 



The purpose of this paper was to determine to what extent light can 

 be thrown on the problems of metabolism in the plant by means of re- 

 actions, the results of which are viewed under the microscope. This 

 method of investigation, as indicated in the titles of the books by Tun- 

 mann^ and by Molisch," is usually called microchemistry. Micrometabol- 

 ism perhaps better expresses the point of view from which this present 

 investigation was undertaken. Nereocystis luetkeana was chosen on ac- 

 count of the attention that kelp beds have been given economically, and 

 because no previous work of this nature has been done on it. The present 

 paper deals only with the inorganic constituents of the cell and the com- 

 position of the cell wall. 



INORGANIC CONSTITUENTS 



Many chemical analyses have been made of the kelps of the Pacific 

 Coast. Balch^ was the first to call attention to the large quantities of 

 potassium and iodine. Later Stewart* made a detailed inorganic analysis 

 and with the exception of iodine found them to contain the same elements 

 as other plants, differing only in the percentages. His table of analyses 

 was made the basis of this work on the inorganic constituents. He found 

 the composition of the ash of the harvestable portions of Nereocystis to 

 be as follows: Ca, 2.10%; Mg, 1.55%; Na, 11.05%; K, 33.66%; 

 FesOg+ALOg, .17% ; CI, 40.89% ; SO,, 4.63% ; CO3, 3.10% ; PO,, 1.91%. 

 Analyses made by Turrentine^ showed .12% iodine in the fronds and 

 .15% in the stipe. 



The methods used in this inorganic analysis were in general those 

 suggested by Tunmann-^ and Molisch^ with a few modifications. Sections 

 about 9 fx thick were taken of the holdfast, stipe and fronds, and washed 

 in distilled water to remove any sea water or cell contents that might be 

 on the surface of the sections. With the exception of the test for iodine, 

 the work has not depended upon color reactions but -on crystals observed 

 under the microscope. Color reactions are useful to locate a substance 



iTunmann, O. Pflanzenmicrochemie. Berlin. 1913. 

 2Molisch, H. Mlcrochemie der Pflanzen. Jena. 1913. 

 sBalch, D. M. Journ. Indust. & Engin. Chem. 1:21-38. 1915. 

 4Stewart, G. R. Journ. Agr. Research 4:21-38. 1915. 

 STurrentine, J. W. U. S. Senate Doc. No. 190:220-221. 1911. 



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