BOTANY. 683 



Petersbvrg, and has been issued as a separate edition. It is in Russian, 

 and is a detailed account of assimilation and related topics. Leclerc, 

 in Ann. Sci. Nat., has a paper on transpiration, where he gives a history 

 of modern theories and discoveries. 



Reinke, in Bot. Zeitung, has a paper on autoxidation in living vege- 

 table cells. He states that in every cell are found autoxidators or sub- 

 stances which, at a low temperature, and by the action of molecular 

 oxygen, can be oxidized in the presence of water, producing peroxide 

 of hydrogen. Wortmann, also in Bot. Zeitung, shows that radiant heat 

 falling on a growing organ causes it to curve to or from the source of 

 heat, and that the phenomena resemble those caused by light. Wieler 

 states that plants grow more rapidly under diminished atmospheric 

 pressure, although beyond a certain point the converse is true. Stahl, 

 in a paper on the influence of light on the growth of plants, Gcs. Med. 

 & Naturwiss. Jena, says that in plants exposed to the light the palisade 

 cells are specially developed, and that in plants growing in dry, sunny 

 places, the leaves tend to assume a vertical position, owing either to a 

 lengthening of the upper side of the leaf-stalk, or more frequently to its 

 upward bending. The difference in aspect of the leaves of the same 

 species when growing in the shade or exposed to the sun arises from 

 the fact that, in the former case, the parts of a leaf lie more nearly in a 

 single plane, while, in the latter case, they are curved and bent in different 

 planes. The action of electric light on the growth of plants has been 

 noticed in several journals during the year, but the results arrived at 

 are unsatisfactory and, at least as far as any practical application of 

 the electric light is concerned, it seems as if little was to be expected. 

 Wiesner, in Bot. Zeitung, maintains that there are two maxima of growth 

 in the epicotyl of Phaseolns multiflorus, and a repetition of his earlier 

 experiments on this point confirms their accuracy. 



The first series of Investigations of the Laws of Grotcfh of Plant Organs, 

 by Wiesner and Wettstein, is devoted to a study of the nutation of in- 

 ternodes. Baranetzki, in Mem. Acdd. Sci. St. Petersburg, has a paper 

 on the nutation and winding of stems. Bengt Joensson, in Bericht. 

 Dcutscli. Bot. Gesell., considers the effect of currents of water on growing 

 plants, or, as he calls it, Rheotroplsmus. He finds that in the Plasmodia 

 of Myxomycetes the growth is against the current, i. e., positively rheo- 

 tropic, while in some mucors it is with the current, or negatively rheo- 

 tropic. Pfeffer has an important communication in the same journal, 

 Locomotorisclie Richtungsbeicegungen dvrch chemiscJie Reize. He states 

 that the antherozoids of ferns are attracted by the malic acid given off 

 by the open archegonia, while in mosses the antherozoids are attracted 

 by cane sugar. Capillary tubes filled with a weak solution of malic 

 acid or its salts can be used for attracting the antherozoids of ferns, 

 which will enter the mouth of the tubes. Zoospores of Saprolegnia are 

 attracted by the denser parts of solutions in which any good nourishing 

 material is unequally distributed. 



