214 Pennington — A Cliemico-PJiysiological 



crystal, one form having, normally, four pointed arms of 

 equal length radiating from a centre. Sometimes these 

 arms were broken off or splintered, or the crystals other- 

 wise maltreated, so that fragments could be seen lying 

 about. The size of these crystals was very variable. 

 They proved to be calcium oxalate, and as such were first 

 described by Mann. * He gives seventeen as the number 

 found in a single cell. In the material studied here more 

 than twenty were sometimes counted. 



Another form had four short arms, two or three times as 

 broad as the oxalate crystals. The arms were smooth and 

 did not show any tendency to splinter. Though they 

 varied considerably, some attained a much larger size than 

 the oxalate crystals ever reached. Occasionally one was 

 found having a diameter more than half that of the cell. 

 They were dissolved by a 10 per cent, solution of caustic 

 potash; likewise by hydrochloric and dilute sulphuric acid. 

 Sulphuric acid in alcohol gave a precipitate of calcium 

 sulphate. A 2 per cent, solution of acetic acid took these 

 crystals into solution, while a concentrated solution did 

 not affect them. This behavior corresponds to calcium 

 tartrate, and furnished an evidence of the presence of tar- 

 taric acid, which was later confirmed in the gross analysis. 



I have not been able to find any mention in the literature 

 011 this subject of the presence of calcium tartrate crystals 

 in Spirogyra. While not nearly so numerous as the oxalate 

 crystals, their presence was so constant that they may be 

 safely taken as a normal constituent of the plant. 



Trimethyeamine Content of Spirogyra. 



While preparing Spirogyra for use, that is, freeing it 

 from foreign matter, washing, drying, etc., it was noticed 

 that the hands of the operator acquired a fishy odor, as did 

 also the vessels in which the air-dried substance was pre- 

 served, and that, while drying, the same odor could be 

 distinctly detected. Drying at ioo° C. to constant weight, 



*Proc. Bot. Soc. of Edinburgh, Vol. 18, (1890). 



