[Vol. 2 



806 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Results. — These negative results do not necessarily argue 

 against the production of slime through the agency of 

 enzymes. It is impossible to exactly reproduce the conditions 

 of the cell in vitro, and enzymes which might act upon cellu- 

 lose in the living tissue to j)roduce slime might easily be in- 

 hibited from action on cellulose or hemicellulose under the 

 conditions of the experiments. Griiss ( '10) found that fresh 

 cherry gum contained cytase, but that none was demonstrable 

 in the older gum. He also found that malt diastase would 

 not act upon such gum until the tannins had been removed. 

 It is known that the algae do contain tannins or ' ' tannoidal ' ' 

 bodies, the writer having demonstrated a "tannoid" content 

 in Ascophyllum of 1.1 per cent of the dry weight. These, or 

 other agents, could be involved in the partial or complete in- 

 hibition of cytolytic action. On the other hand, indirect evi- 

 dence, at least, points to the presence of the galactan and 

 pentosan groups as due to their being laid down as such, that 

 is, they do not arise as the direct result of hydrolytic enzyme 

 action, but probably represent the final step in the condensa- 

 tion of those particular hemicelluloses. Tschirsch ('89) and 

 his students have shown that the algal slime exists as an in- 

 tracellular substance, and they hold that in most instances, 

 at least, it does not arise from the cellulose. This seems to 

 be the logical view, and we in turn seem justified in looking 

 upon the galactan and pentosan groups in the algae as normal 

 products of the plant's metabolism, present at all stages in 

 the plant's growth, and capable of giving rise to gelatiniza- 

 tion at any time upon the adsorption of water. If one ex- 

 amines, for instance, such forms as Fucus, Mesogloea, and 

 Chondrus, the slime is hardly detectable when the plants are 

 growing under normal conditions, but when brought into the 

 laboratory and placed in fresh water, a rapid adsorption 

 begins at once. The dissolved salts in sea-water are un- 

 doubtedly the inhibiting factors in such adsorption under 

 normal conditions. 



That this inhibition is not bound up with the living cell may 

 be shown by the simple experiment of killing two fronds of 

 Chondrus, for example, and placing one in fresh, the other 



