[VoL. 2 
826 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
forms. In the filamentous forms he showed the presence of 
oxidases by the formation of colored granules within the cells 
surrounded by these reagents. Reed concludes that oxidases 
of specific oxidative ability are very generally present in the 
algae, and where negative results are obtained, either the 
necessary specific compound is not present or other factors 
enter in, such as the destruction of the oxidase equilibrium of 
the cell upon crushing. 
Catalases—Both fresh and air-dried tissue were used for 
catalase demonstration. In a preliminary series, the addition 
of 5 ce. of 3 per cent hydrogen peroxide to about a gram of 
fresh crushed algal tissue showed evolution of oxygen in all 
cases except one, that of Mesogloea. Later, a series (table x1x) 
TABLE XIX 
CATALASE ACTIVITY OF CERTAIN ALGAE 
Number cc. O: evolved at 21.5°C. 
Alga 
2 minutes 5 minutes 10 minutes 
Ascophyllumt. 05 ose cn oe 3 9 a9) 
LOMANGTI Aes ae ee 1.4 hee} D6) 
Mesogloeay is « «insei- clei ioeteys 0.0 0.0 0.0 
OUT a aicectoinin itoman ete oo a2, A a5 
Algardhiellas v2: ace oce Sisk: 4.6 5.6 
ChONGTUS pee. A Sere A 2.0 Deak) 
Rhodymenta.......0..5.0- 9 1.4 2.0 
Ceram eee Soll 5.9 8.2 
Potato leaf tissue......... 22.6 ots s See 
was set up in which 1 gram of powder was placed in 125 ce. 
Erlenmeyer flasks, 10 cc. of 38 per cent hydrogen peroxide 
added, and the oxygen evolved collected in a gas burette over 
water. The flask in which the action was taking place was 
shaken every 15 seconds, and the volume of oxygen evolved 
read at the end of 2, 5, and 10 minutes. The temperature of 
the room was practically constant during the experiments and 
no especial precautions were taken to control the temperature 
of the flask other than keeping the hands away from it dur- 
ing the action. The results are not meant to be quantitatively 
exact, but they do give the relative catalase activity of the 
several forms. In addition, air-dried potato leaf tissue that 
had been in the laboratory about the same length of time as 
the algal tissue was tested for comparison. 
