324 BOTANICAL GAZETTE. 



laboratory at Bonn. The most successful method is as follows: Very thin 

 radial and tangential sections of the cortical tissue of various trees or shrubs 

 were treated on the slide, first with dilute and then with concentrated sulphuric 

 acid. After carefully removing the acid with a pipette, the sections were 

 washed thoroughly with distilled water and covered with glycerine. By this 

 treatment the cell-wall (and often the middle lamella) is destroyed, and the 

 protoplasmic thread between adjacent cells distinctly seen. The material for 

 this woil: is best gathered in January. Sections may be cut from fresh speci- 

 mens or from those which have lain some days in absolute alcohol. In the 

 first case, however, the razor must be flowing with absolute alcohol. 



The recent experiments of R. Hartig to determine the tissue through 

 which water moves in the plant, and the causes of the movement, lead him to the 

 following conclusions : There are two types of trees, in one of which (e. g. oak) the 

 duramen is incapable of conducting water, and the other (e. g. birch) in which 

 the whole of the wood is conductive. Tracheides, and at times true vessels, are the 

 chief organs for the transference of sap. The absorption of water by the roots 

 is due to the osmotic forces in its cells, especially those of the root-hairs. The 

 cause of the ascent of water in wood is the difference in density of the air in 

 the conducting organs, and the pressure of the atmosphere exercises little or no 

 influence on it. 



ARTICLES IN JOURNALS. 



" Analyst, An."— A Granule of Starch, Pop. Sci. Mo. 23. 687. 



Baker. .). G —A synopsis of the genus Selaginella (5 new species, all from Central and S. 



Am.), Jour. But. 21. 210: Ferns collected by the Rev. Hanning in E. Tropical Africa 



(two new species, an Asplenium and a Notochlsena), 1. c. 245: A study of the survival 



of the fittest, 1. c 271. 

 Boswell, H.— Two recent additions to the British Mosses (one being Sphagnum Torrey- 



anum, Sulliv. ), .lour. Hot. 21. 233. 

 Buckley, S. B.— Some new Texan plants (4 species, all shrubs or small trees, one being a 



Quercus), Torr. Bull. U> 90. 

 Christy, Robert Milleb and Henry Corder.— Arum maculatum and its cross-fertiliza- 

 tion, Jour. Bot. 21. 225 and 262. 

 Corder, Henry.— See under "Christy " above. 



Ellis, J. B. and B. M. Everuart.— New species of Fungi (7 species), Ton. Bull. 10. 89. 

 Everhart, B. M.— See under " Ellis" above. 



Greene, Edward Lee..— New Western Composite (9 species) Ton. Bull. 10. 86. 

 Grove, W. B. — A new Puccinia, Jour. Bot. 21. 274. 

 Hance, II. F.— Orchidaceas quattuor novas Sinenses, Jour. Bot. 21. 231; Hep tad em Pili- 



cum Novarum Sinicarum (7 species), 1. e. 267 : Disporopsis, genus novum Liliacearum 



(from China), 1. c. 278. 

 Hems ley, W. Botting. — Bermuda plants in the Sloanc collection, British Museum, (with 



plate and description of a new Carex) Jour. Bot. 21. 257. 

 HILL, E, J. — Potamogetons in W. New York. Torr. Bull. 10. 92: Means of plant dispersion 



(continued from August number), Am. Nat. 17. 102S. 

 Kidd, H. W.— Notes on rasciated stems (with cut), Sci. Gossip, No. 225. 196. 

 Pim, Greenwood. — On Alliospora. a supposed new genus of Dematiei, Jour. Bot. 21. 334. 

 Roze, E. — Male organ of Azolla filiculoidea Lam.. Bull. Soc. Philom. ele Paris, Ser. 7. 7. 133. 

 Sgribner, F. Lamson.— Notes on Spartina (with plate), Torr. Bull. 10. 85. 

 Sedgwick, W. T.— Symbiosis and Vegetating Animals (Review of controversy between 



Brandt, Geddes, Lankesteret al.), Pop. Sct'.Mo. 23 811. 

 Trelease. W— Notice of Farlow's notes on Ellis' N. Am. Fungi, Science, 2. 410. 

 Vqgel, August. — The colors of flowers (considered chemically), Pop. Sci. Mb. 23. 837. 

 Ward, Lester F. — Marsh and aquatic plants of the Northern U. S., many of which are 



suitable for carp ponds, Bull. V S. Fish Com. 3. 2V7. 



