1907] CURRENT LITERATURE 357 
engaged in division. The figures support what the author regards as a general 
law, that the rate of accretion varies inversely with the size of the organism. There 
is nothing particularly new about that, but there is value in abundant data.— 
Raymonp H. Ponp 
Mechanics of plants.—Lorcu describes the arrangement of mechanical 
tissues in a number of mosses and the warping effects produced thereby in absorb- 
ing or losing water.33 His observations upon the circinate inrolling of Leptodon 
Smithit and some allies, and the behavior of leaves possessing mechanical tissues 
in ribs and borders, as the Polytrichaceae, are interesting, but develop nothing 
specially novel. The same may be said of the study of the mechanical system of 
the hyaline cells in Sphagnum leaves.34+—C. R. B 
Respiration.—A rather startling announcement is that by SroKiasaSs and his 
assistants that in coal and lignite they find an enzyme, peroxidase; and by com- 
parative experiments on sterilized and non-sterilized coals, following the methods 
of PALLADIN and his pupils, they recognize the excretion of CO. as dependent 
partly upon autoxidation and partly upon enzymic action. The excretion of 
methane and hydrogen is due to the peroxidase.—C. R. B. 
Secretions of enzymes.—PANTANELLI has continued his study of this topic, 
of which he presents a detailed account.3° Though he has recorded the effect 
of many substances upon the formation and action of invertase in Mucor, he has 
not been able to throw much light upon the deeper problem of the method of 
secretion.—C. R. B. 
Physiology of movement.—The New Phytologist is printing an interesting 
series of lectures on this subject by Mr. FRANCIS DARWIN, beginning in the number 
for November 1906.37—C. R. B 
33 Lorcu, W., Einige Bewegun 1 Scl f h n an den Achsen 
und Blattern mehrerer Laubmoose de ee des wuctguts von Wise: Flora 97:76- 
95: - 20. 1907. 
, Das mechanische System der Blatter, insbesondere der Stimmchen- 
el yon Sebagaach, Idem 97396-1006. figs. II 
35 STOKLASA, J., A. Ernst and K, Cuocensx‘, Ueber die anaérobe Atmung der 
Samenpflanzen wie die non der Atmungsenzyme. II. Ber. Deutsch. Bot. 
Gesells. 25:38-42. 1907. 
36 PANTANELLI, E., Meccanismo di secrezione degli enzimi. Annali di Bot. 5:229- 
272, sean ae 
ted stimuli. Nov. 1906. II. On some questions of nomenclature 
and teri Dee. 1906. III. The analysis of geotropism. Jan. 1907. EV: 
localisation of perception, Feb. 1907. 
