232 Puget Sound Marine Sta. Puh. Vol. 1, No. 21 



furfurol upon hj^drolysis. As in Fucus, algin was found to give a blue 

 reaction with iodine in potassium iodide and sulphuric acid. 



Sections of the different tissues of Nereocystis were placed in copper- 

 oxyammonium. Potato sections were used as a check, since their cell walls 

 are known to be cellulose. These sections were completely dissolved at 

 the end of 36 hours, but sections of the holdfast, stipe and fronds of Nereo- 

 cystis were not dissolved at the end of that time; consequently they were 

 allowed to stand 5 days longer. At the end of this time no further action 

 had taken place. This shows that if cellulose was present it did not com- 

 pose the entire wall, and that at least part of the wall was made up of 

 a substance that was insoluble in copperoxyammonium. 



Some sections were then put in a dilute sodium carbonate solution 

 and left for about 48 hours ; at the end of this time the sections were 

 very soft and the cells easily broken apart. These were also left in the 

 solution for a longer period of time, but at the end of 8 days they still 

 retained their cellular structure. These sections were washed with water 

 and then put into copperoxyammonium. At the end of 48 hours they 

 were entirely dissolved. Since cellulose is dissolved in copperoxyammo- 

 nium, and algin in sodium carbonate, it seems evident that the cell wall 

 of Nereocystis is made of cellulose and algin. Whether the algin forms 

 a loose chemical compound with the cellulose or whether it merely forms 

 a layer around the wall could not be determined. Since the cells were 

 easily broken apart in the sodium carbonate solution, there seems to be 

 an indication that algin may form a part of the substance which holds the 

 cells together. 



SUMMARY 



1. The inorganic constituents of Nereocystis luetkeana can be dem- 

 onstrated microchemically in the cells of the fronds, stipe and holdfast. 



2. The cell wall seems to be made up of cellulose and algin. 



3. Probably algin is the principal substance that holds the cells 

 together. 



Acknowledgements are due Dr. G. B. Rigg of the University of 

 Washington and Dr. T. C. Frye, Director of the Puget Sound Marine 

 Station, for suggestions and criticisms. 



