538 Physiologie. — Algae. 



ASO, K. , Studies on the Lability oi Enzyms. (Bul. 

 College of Agriculture, Tokyo. Vol. VI. No. 2. 1904.) 

 The author draws irom his experiments the following con- 

 clusions: 



1. Enzyms in high dilution are not killed by small quanti- 

 ties of dicyanogen. Hereby another essential difference between 

 the chemical behavior oi the living protoplasm and that of 

 enzyms is etablished. 



2. Nitrous acid in very high dilution is more injurious for 

 enzyms than equally diluted nitric acid. 



3. Hydrazine, methylhydrazine and hydroxylamine in dilute 

 neutral Solutions destroy the activity of enzyms. This would 

 be best explained if the active grouping in the enzyms are 

 either aldehyde or ketone groups. According to Loew's pre- 

 sent view, ketone groups alone can come here into consideration. 



Loew. 



BäRNES, C. R., The significance of Transpiration. 

 (Science. N. S. Vol. XV. Mars 21, 1902. p. 460.) 



Abstract of paper read before the 3rd Annual meeting of 

 the botanists of the Central States. Holds that while trans- 

 piration is necessary and unavoidable it is itself a constant 

 menace to life. The double functions of transpiration, of 

 carrying mineral salts to the leaves and of concentrating the 

 Solutions there are held to be to some degree mutually exclusive. 



H. M. Richards (New York). 



Beesley, L., AFountain Alga. (The New Phytologist. III. 

 No. 3. March 1904. p. 74—82. pl. 1. figs. 74, 75 in text.) 



Describes the life-history of a new fresh-water alga, bearing a re- 

 semblance to Gongrosira, but diifering from it in having no encrustation 

 of carbonate of linie on the contrary, its natural substratum is a siliceous 

 one. The zoospores also are not formed in terminal and swollen zoo- 

 sporangia as in Gongrosireae. Neither formal diagnosis nor name are 

 given to this new alga. Its characteristics are as follows: It is siliceous 

 in habit and grows in running water of low temperature, forming an 

 irregularly-branched, star-shaped or circular thallus, the cells of which 

 are longer than broad, containing a parietal chloroplast and no pyre- 

 noids. By continuous division, beginning always at the centre of the 

 thallus, the cells break up into zoosporangia, from which issue iour 

 zoospores. The thallus may pass into a palmelloid condition, and in this 

 condition the cells divide at once to form a) zoospores, or b) daughter- 

 cells which repeat the process. The zoospores are bi-ciliate and pear- 

 shaped, with basin-shaped chloroplast. red eye-spot and colourless ante- 

 rior portion. They germinate without any period of rest into a new 

 plant. No sexual stage is known. The laboratory methods of cultivation 

 are described and figured. E. S. Gepp. 



Cushman, JOSEPH A., Desmids from southwestern Colo- 

 rado. (Bulletin of the Torrey Botanical Club. XXXI. 

 p. 161 — 164. PI. 7 March 1904.) 



A list of seventeen species, collected at an altitude of 3,540 meters. 

 The following new varieties are given : Penium closterioides spirograna- 



