434 



SCIENCE 



[N. S. Vol. XLIV. No. 1134 



mining the effect which spices have on micro- 

 organisms. Here the spice or condiment is 

 mixed with the agar and poured on one side 

 of the plate, plain agar on the other and streaks 

 of the organism in use made across both. A 

 modification in the method of preparation has 

 been adopted which obviates the necessity of 

 using rods or metal strips. This consists of 

 cutting semi-discs of muslin (cheesecloth) 

 which are sterilized in the petri dishes. Plain 

 agar is poured over the entire dish and then 

 when the agar is hard the piece of cloth with 

 adherent agar is taken out from each petri 

 dish with sterile forceps and into its place is 

 poured the agar containing the condiment to 

 be tested. The cloth semi-discs are more 

 easily prepared than the rods and the 

 union between the agar in the two halves of 

 the plate is more direct. This, we take it, is 

 an advantage since it readily permits of diffu- 

 sion. The agar clinging to the cloths need 

 not be wasted but may be saved by throwing 

 the cloths into a funnel and allowing the agar, 

 when liquefied, to drain off into a flask. In- 

 stead of plain nutrient agar, potato or wort 

 agar, gelatine or other liquefiable solid media 

 favorable to the growth of organisms to be 

 studied, may be used. 



The accompanying figures illustrate the 

 method of use and the character of the results 

 obtained. "W. D. Frost, 



Freda M. Bachmann 



Department of Bacteriology, 

 Wisconsin Agricultural Exp. Sta., 

 Madison, Wis. 



SOCIETIES AND ACADEMIES 



ST. LOUIS ACADEMY OF SCIENCE 

 At a meeting of the St. Louis Academy of Sci- 

 ence on March 20, 1916, Dr. A. R. Davis, of the 

 Missouri Botanical Garden, presented a paper on 

 "Enzyme Action in Marine AlgEe," of which the 

 following is an abstract: 



During the years 1914-15 a general survey was 

 made of the enzymes of certain representative ma- 

 rine algse. The work was carried on for the most 

 part at the Woods Hole Biological Laboratory 

 since fresh, vigorously growing plants were ob- 

 tainable in that immediate vicinity. Plants were 

 also collected and carefully dried and with this 



material the work was further prosecuted at the 

 Missouri Botanical Garden. All investigations 

 where dried tissue was involved, however, were 

 later duplicated with fresh material at Woods 

 Hole. The standard methods of enzyme isolation 

 and determination were employed and where nega- 

 tive results were obtained many modifications of 

 these methods were brought to bear. In sum- 

 marizing the results obtained, two striking points 

 stand out, i. e., the relative paucity of the number 

 of enzymes demonstrable by standard methods, 

 and the extraordinary slowness with which most of 

 these enzymes act. Especially were both these 

 points true for the "browns." In Ascophyllum 

 and Fucus of this group catalase was the only 

 enzyme demonstrable, while in Laminaria and 

 Mesogloea diastase, lipase, proteinases and cata- 

 lase were found. Enzyme action was much more 

 easily shown in the ' ' reds ' ' and the ' ' greens ' ' 

 where in addition to the ferments found above, 

 dextrinase, tryptase, ereptase and nuclease could 

 be demonstrated. Oxidase was shown in but two 

 forms, Agardhiella and Viva. The rate of action 

 in these two groups was also much faster than it 

 was in the ' ' browns, ' ' although here too, such ac- 

 tion was slow when compared with that of many 

 of the higher plants. 



The carbohydrases found were those acting 

 upon such polysaccharides as starch, glycogen, dex- 

 trin and laminarin — in no case any of the disac- 

 charides employed being attacked. This latter 

 fact is especially interesting in the light of the 

 role maltose plays in the assimilation of the 

 higher carbohydrates. Lipases and nucleases were 

 quite widely distributed, and proteinases (tryptic 

 and ereptic) were demonstrated in most of the 

 forms investigated. Casein and peptone in neutral 

 and slightly alkaline solution proved the most 

 favorable substrates for these latter enzymes, al- 

 though albumin and legumin were also hydrolyzed 

 in certain instances. There was no digestion of 

 algal protein, as shown by autolytic experiments, 

 and no splitting of amino acids. 



Several factors may enter in to account for the 

 limited number of enzymes formed and the slow- 

 ness of their action: (1) they may be formed in 

 small amounts in the tissues, or as formed may be 

 inherently slow; (2) inhibiting substances may be 

 liberated upon crushing the cell which may cut 

 down the rate of action or destroy it altogether. 

 Evidence is at hand tending to show that both of 

 these factors may be concerned. 



J. M. Greenman, 

 Corresponding Secretary 



