1914) 
DUGGAR AND DAVIS—FUCUS VESICULOSUS 425 
tions of experiments and minor modifications in technique not 
referred to in this preliminary account. Тһе nature of the 
results, furthermore, made it seem desirable that a much more 
general study be made of the abundance and distribution of the 
enzymes in the various families of the marine alge, and such an 
investigation is now in progress by one of us. 
It would seem idle to attempt here an explanation of the nega- 
tive results obtained, yet two or three possibilities have occurred 
to us which may be mentioned. Тһе conditions of life of the 
Fucacee, especially the temperature relation, make it possible 
to suspect that metabolic changes occur at a very slow rate. If 
this is the case, it might be assumed that the commoner metabo- 
lic enzymes might be present in such small quantity that an 
indication of their presence would not be apparent by utilizing 
the methods ordinarily employed. The very fact that the 
capacity for food accumulation, that is to say, the "storage" of 
food materials, has not become highly developed in these forms 
suggests that the usual enzymes might not be found in abun- 
dance. Nevertheless, if such is the case, it may be pointed out 
that the present methods of enzyme work are very inadequate 
when applied to metabolic processes in general dealing with the 
transformation of products which do not accumulate in some 
quantity in the cell. In this connection attention may be 
drawn to Arber’s (’01) observation on the slow rate of trans- 
formation of starch in the thallus of Ulva latissima, where a 
darkening period of from three to five weeks was required for 
the disappearance of this product. 
The other possibility which has suggested itself is that in the 
cells of the Fucacee there may occur inhibiting substances which 
upon the death of the cell may form with the enzymes com- 
pounds from which the ferments cannot be again recovered. 
We have no evidence of the existence of any such bodies. Fur- 
ther investigation of Fucus and related alge should perhaps 
throw some light upon the negative evidence produced by our 
extensive data. 
Graduate Laboratory, Missouri Botanical Garden. 
