72 BOTANICAL GAZETTE [july 



phosphates are precipitated out quantitatively, and scant growth occurs; 

 (2) when glycerol phosphate is used, the phosphorus stays in solution and 

 better growth results; (3) the use of protective colloids (agar and potassium 

 silicate) to prevent precipitation is accompanied by beneficial results; 

 (4) mechanical agitation of the cultures greatly improves the growth by hasten- 

 ing the solution of CaCOj, and thus maintaining the proper reaction. In the 

 course of the work an all-glass apparatus for the determination of nitrogen was 

 devised." — J. J. Willaman. 



Distribution of dissolved oxalates in phanerogams. — Molisch'^ finds 

 dissolved oxalates appearing rather generally distributed in phanerogams. 

 All investigated species of the following families bear much dissolved oxalate: 

 Polygonaceae, Chenopodiaceae, Amarantaceae, Aizoaceae, Begoniaceae, 

 Melastomaceae, Oxahdaceae, Cannaceae, and Marantaceae. While in most 

 cases this chemical character, like many other chemical characters, runs by 

 families, this is not always the case. In certain families some genera are very 

 rich in dissolved oxalates, while other genera contain little or none; this is 

 true of Commelinaceae and Cactaceae. — Wm. Crocker. 



Water movements in plants. — Renner'^ answers Nordhausen's criticism 

 (Ber. 1Q16) of his earlier work (Flora, 191 1) on water movement in plants, 

 and gives a number of experiments to confirm, in the main, his earlier generali- 

 zations. He also gives a brief statement on the "saturation deficit" and the 

 "energetics of water movement" in plants. — Wm. Crocker. 



Turgor and osmotic pressure. — Thoday'-' gives a simple elementary 

 analysis of turgor, osmotic pressure, and saturation deficit relations of plant 

 cells and the conditions that lead to the movement of water from cell to cell 

 in the plant. The article ought to do much to clear up the confusion in refer- 

 ence to this field. — Wm. Crocker. 



Hydnaceae of North Carolina. — Coker's has published a monograph of 

 the Hydnaceae of North Carolina, illustrated by numerous excellent photo- 

 graphic plates. Six genera are presented, represented by 29 species, 2 new 

 species being described in Hydnellum and i in Phellodon. — ^J. M. C. 



" .^LLEN, E. R., and Davisson, B. S. An all-glass nitrogen apparatus. Ann. 

 Mo. Bot. Gard. 6:45-48. 1919. 



'- MoLiscH, Hans, tjber den Microchemischen Nachweis und die Verbreitung 

 gelorter Oxalate im Pflanzenrmche. Festschrift zum Ernst Stahl. pp. 60-70. 

 Jena. 191S. 



" Renner, O., Versuche zur Mechanik der Wasserversorgung. Ber. Deutsch. 

 Bot. Gesells. 36:172-179. 1918. 



'■< Thoday, D., On turgescence and the absorption of water by the cells of plants. 

 New Phytol. 17:108-113. 1918. 



'5 CoKER, W. C, The Hydnums of North Carolina. Jour. Elisha Mitchell Sci. 

 Soc. 34:163-197. ph. 2g. 1919. 



