[Vol. 2 



802 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



The action of the potato extract upon starch was about two 



and one-half times that of TJl 



and 



action on dext 



about twice in all of the determinations made. For some un- 

 known reason the hydrolysis of dextrin by the diastase from 

 Ulva ceased after the twenty-eighth day. 



table x 



A COMPARISON OF THE DIASTATIC ACTIVITY OF ULVA WITH THAT OF POTATO 



LEAF TISSUE 



Substrate 



Sugar as glucose in 5 cc. 



mgms. 



50 cc. 



14 days 



21 days 



28 days 



35 days 



42 days 





Ulva 



Potato 



Ulva 



Potato 



Ulva 



11.8 

 17.8 



Potato 



Ulva 



Potato 



Ulva 



Potato 



Starch .... 

 Dextrin. . . 



8.7 

 10.5 



18.1 

 17.3 



9.6 

 11.5 



26.3 

 25.1 



28.1 

 27.5 



12.9 

 17.9 



33.5 

 30.3 



13.8 

 17.9 



35.5 

 31.9 



ACTION OF VARIOUS ALGAL EXTRACTS UPON THE CARBOHYDRATE 



CONSTITUENTS OF AGAR-AGAR, AND OF VARIOUS GUMS, 

 AS WELL AS EXPERIMENTS UPON THE AUTOLYSIS 



OF ALGAL SLIME 



Because of the large amounts of carbohydrate-containing 

 slime formed by many algae, and because of the role this 

 might play as a reserve product, it was deemed advisable to 

 try out the various algae for enzymes capable of hydrolysing 

 such complex carbohydrates to assimilable sugars. It was 

 assumed on the basis of the work done by Konig and Bettels 

 (*05) and others, that such hydrolytic products would be re- 

 ducing sugars, in all probability galactoses and pentoses. 



A series was set up with each of the several algae, using 

 50 cc. of .25 per cent agar as a substrate and varying amounts 

 of a "diffusion-extract" from fresh tissue, 

 strate was slightly viscous in the cold, but when kept at a 

 temperature of 40° C, the optimum temperature for diastase, 

 this was not noticeable. Toluene was used as an antiseptic. 

 The flasks were shaken at regular intervals during a 30-day 

 period and at the end of that time aliquot portions were re- 

 moved and tested for reducing sugars. There was no reduc- 

 tion in any case. 



As a parallel series, thin strips of agar were placed in test- 

 tubes and 20 cc. of "diffusion-extract" added. Toluene was 

 used as an antiseptic and the tubes kept at a temperature of 

 40° C. for two months. At the end of that time no hydrolytic 



The agar sub- 



