[Vol. 2 



800 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



It diffused readily in water with no resulting viscosity. Ten 

 cc. of the "diffusion-extract" were used for enzyme action, 

 toluene added, and the flasks kept at a temperature of 21-23 °C. 

 for 100 days. The data here obtained are given in table vm. 

 Dextrin here more nearly approaches starch as a favorable 



substrate, differing from the action evidenced by the other 

 algae with the exception of Laminaria, where all action was 

 slow. There is also a slightly increased action over that evi- 

 denced by Rhodymenia, for all the carbohydrates hydrolysed. 



THE CARBOHYDRASES OF CERAMIUM RUBRUM 



As was the case with Rhodymenia, it was necessary here 

 to use 20 volumes of the water-extracting medium, not, how- 

 ever, because of the great viscosity, but on account of the 

 great adsorption of water by the tissue particles. The alcohol 

 precipitate was copious and finely flocculent. It diffused in 

 water rather slowly, giving a mixture that was only slightly 

 viscous. Ten cc. of the "diffusion-extract" were used for 

 action, the usual percentage of toluene added, and the flasks 

 maintained at a temperature of 21-23 °C. for 100 days, 

 data are given in table ix. 



The 



TABLE IX 



THE ACTION OF A "DIFFUSION-EXTRACT" FROM FRESH CERAMIUM TISSUE UPON 



CERTAIN CARBOHYDRATES 



Substrate 





Sugar as glucose in 5 cc. 



mgms. 







15 days 



45 days 



75 days 



100 days 



Starch 



6.85 

 11.5 

 Trace 



7.2 



» « » f 



• • • • 



• • » • 



• • • • 



8.1 



15.0 



6.2 



9.4 



• • • • 



Trace 



t * * * 



Trace 



11.75 

 17.5 

 7.3 

 12.1 



Trace 

 Trace 



• t • * 



Trace 



16.9 



Dextrin 



19.6 



Glycogen 



Laminarin 



Inulin 



8.85 

 12.2 

 Trace 



Sucrose 



Trace 



Lactose 



Trace 



Maltose 



Trace 





^» • ^*' ^#* ^ta^* 



Dextrin proved the most favorable substrate for the carbo- 

 hydrate enzymes of this alga, the hydrolysis being about the 

 same as that evidenced by Agardhiella. With the exception 

 of glycogen, the other carbohydrates showed a decreased 

 hydrolysis when compared with this latter form, and when 



