308 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ing themselves saprophytically when occasion requires. This kind of 

 nutriment is presented in much larger quantities on the surface of 

 smaller than of larger lakes. 



Primitive Algae and Flagellata.* — Dr. F. F. Blackman gives a use- 

 ful resume of the work done with the lower Algae (including Chlamydo- 

 monadeaa and Phacoteaa) since Wille's account of the green Algaa in 

 Engler and Prantl's PJlanzenfamilien (1890). Wille's classification is 

 taken as the starting-point, with the additions and alterations rendered 

 needful by recent observations and discoveries. A full bibliography is 

 appended. 



Fungi. 



Enzymes of Fungi. f — P. Kohnstamm has made a study of the en- 

 zymes which attack starch, glucosides, proteids, and cellulose, in those 

 fungi which destroy wood, especially Agaricus melleus, Merulius lacry- 

 mans, and Polyporus squamosus. The mode of treatment is described 

 in detail, and the following is an epitome of the most important results 

 obtained. 



From all the three fungi named, a starch-destroying enzyme (amy- 

 lase) was obtained, apparently identical with the diastatic enzyme of 

 malt ; it was found in the largest quantity in Polyporus squamosus. A 

 glucoside-decomposing ferment (emulsin) was found in M. lacrymans 

 and P. squamosus, but not in A. melleus. A proteolytic enzyme was 

 displayed only feubly by A. melleus, more strongly by M. lacrymans and 

 P. squamosus. A cellulose-decomposing enzyme (cytase, cellulase) was 

 found with certainty only in Merulius. It was established that these 

 various ferments may act simultaneously. 



In Polyporus squamosus it would appear that the fermenting sap is 

 produced only by the receptacle ; in Merulius lacrymans the mycele has 

 also this property. The action of emulsin is especially seen in the de- 

 struction of the coniferin in Conifers, and in the action of P. squamosus 

 on the aesculin of the horse-chestnut. It is the hadromal of Czapek ; J 

 that possesses the property of setting free the cellulose, and thus ex- 

 posing it to the action of a cellulase. 



Amylomyces.§ — A. Sitnikoff and W. Rommel give the results of a 

 series of culture experiments on different media of the various ferment- 

 ing forms of Mucor included under the term Amylomyces, especially 

 those known as Amylomyces Bouxii, (3 Amylomyces, and y Amylomyces. 

 Especial attention was given to the fermenting properties of these 

 different forms. 



Propagation of Nectria ditissima.|| — The analogy of the canker 

 of apple-trees caused by this fungus with human cancer has induced 

 M. Descours-Desacre to carry out further investigations as to the mode 

 of propagation of the fungus. The appearance of the disease is, as a 

 rule, preceded by that of Aphis Lachnus-Erisconia on the branches- and 



* Ann. of Bot., xiv. (1900) pp. 647-88; xv. (1901) p. 192 (2 figs.). 



t Beih. z. Bot. Centralbl., x. (1901) pp. 90-121. Cf. this Journal, 1896, p. 656. 



♦ Cf. this Journal, 1899, p. 515. 



§ Zeitsclir. f. Spiritus-Industrie, xxiii. (1 pi. and 2 figs.). See Bot. Centralbl., 

 lxxxv. (1901) p. 164. Cf. this Journal, ante. p. 68. 



|! Comptes Rendus, cxxxii. (1901) pp. 438-9. Cf. this Journal, 1899, p. 631. 



