1915] 



DAVIS — ENZYME ACTION IN MARINE ALGAE 785 



were selected that were ' ' clean. ' ' This was an important pre- 

 caution, since many adhering organisms have been found to 

 be quite active enzymatically, and the presence of even a few 

 might well lead to serious errors in the final results. The fol- 

 lowing forms lent themselves most readily to the work i 1 



Chlorophyceae 



JJlva lactuca (L.) Le Jolis 



Enter omorpha intestinalis (L.) Link 



Phaeophyceae 



Laminaria Agardhii Kjellm. 

 Ascophyllum nodosum (L.) Le Jolis 

 Mesogloea divaricata (Ag.) Kutz 



Rhodophyceae 



Ceramium rubrum (Huds.) Ag. 

 Agardhiella tenera (J. Ag.) Schmitz 

 Rhodymenia palmata (L.) Grev. 

 Chondrus crispus (L.) Stack. 



Preparation of algal material. — In addition to the question 

 of cleanliness, great care was taken to select only plants that 

 were in a young, vigorously growing condition. These were 

 brought into the laboratory, placed in large aquarium jars 

 containing salt water, picked over, and all detectable foreign 

 matter removed. A thorough washing in running salt water 



Q±± TT MO"lU & '" * """'"t) 



for two hours was then given, after which, with the exception 

 of one or two forms that rapidly gelatinized, the plants were 

 placed in running fresh water for 10 or 15 minutes. This 

 fresh water treatment was very efficacious in causing small 

 snails and other minute marine organisms to loosen their hold. 



The plants so washed were either crushed and used at once 

 with the substrate for enzyme action, or they were dried for 

 future use. In either case, two general ways of using the ma- 



1 With the exception of Lammaria Agardhii and Agardhiella tenera, these 

 binomials conform to the nomenclature as given by Farlow (Marine algae of 

 New England, pp. 1-210. pi. 1-1J+. 1881); these two forms are as given by De 

 Toni ( Sylloge Algarum 3: p. 349. 1895) and Engler and Prantl (Nat. Pflanzenfam. 

 1 s : 371. 1896), respectively. 



