March, 1920] PHTSIOLOGT 117 



795. Waldron, L. R., and J. A. Clark. Kota, a rust resisting variety of common 

 spring wheat. Jour. Amer. Soc. Agron. 2: 187-195. Fig. 1-3. 1919. — See Hot. Absts. 3, 

 Entry 484. 



796. Weiimer, C. Leuchtgaswirkung auf Pflanzen. [Effects of illuminating gas upon 

 plants.] Her. Deutsch. Bot. Ges. 36: 140-149. 1918— See Bot. Absts. 2, Entry 614. 



797. Weir, James R. Concerning the introduction into the United States of extra- 

 limital wood-destroying fungi. Mycologia 11: 58-65. 1919. — Attention is called to the 

 absence of quarantine laws providing for a close scrutiny of imported timbers which may 

 harbor wood-destroying fungi. Polystictus persoonii and Trametes atypus which are common 

 and evidently serious rot producers in Japan and the Philippines were found on rotted tim- 

 bers at Bcllingham, Washington. Explanations are presented for the apparent small number 

 of wood-destroying fungi in the tropics, and for the possibility of such species becoming serious 

 pests in the temperate zone. — H. R. Rosen. 



798. Wurth, Th. Vershlag omtrent de werkzaamheden van het Proefstation Malang over 

 1917. [Review of experiment station activities for 1917]. Meded. Proefst. Malang. Java 22: 

 1-20. 1918. — Notes are given on some diseases of Para rubber and coffee. For the former, 

 daily prophylactic disinfection of the tapping cut was found necessary to prevent the 

 spread of canker (Phytophthora faberi) . Die-back (Gloeosporium alborubrum) was severe on 

 trees of all sizes: for the control of it pruning out the diseased parts and spraying adjacent 

 trees with bordeaux mixture are recommended. The brown root disease (Hymenochaele 

 noxia) of coffee was most severe where this crop was planted with Ficus and Hevea. — R. D. 

 Rands. 



799. Young, Harry C, and E. H. Cooper. A method of determining the fungicidal 

 coefficient of lime-sulfur and other common fungicides. Rept. Michigan Acad. Sci. 19 (1917) : 

 221-236. 1918. — The writer formulated a method to determine fungicidal value of fungicides 

 based on the government Hygienic Laboratory method of Anderson and McClintic which 

 determines the bacterial coefficiency of disinfectants by comparing them with a phenol solu- 

 tion of a standard strength. The writer used Glomerella rufomaculans and Endothia parasitica 

 with lime-sulfur, ammoniacal copper carbonate and neutral copper acetate against a copper 

 solution of a standard strength. — G. H. Coons. 



PHYSIOLOGY 



B. M. Duggar, Editor 

 DIFFUSION, PERMEABILITY 



800. Lutman, B. F. Osmotic pressures in the potato plant at various stages of growth. 

 Amer. Jour. Bot. 6: 181-202. 1 table, 2 fig. 1919. — A series of determinations of the osmotic 

 pressure of sap from various regions in the potato plant at various stages in its growth was 

 made by the use of the method of freezing-point depression. The pressure in seed tubers 

 was found to be between 7 and 10.3 atmospheres, but this is considerably lowered by the 

 absorption of water after planting. The juice of leaves from the young plant shows a higher 

 pressure than that from the stalk, and both are higher than that from the seed piece. With 

 the formation of flower buds and young tubers, the pressure becomes greater in the stalk 

 than in the leaves. In the tuber the pressure remains constant from the first. The pressure 

 in the stalk continues high throughout the active tuber and starch period, due to the presence 

 there of an abundant supply of sugar; but with the return of cool weather and the renewed 

 growth of foliage, it is finally exceeded by the pressure in the new leaves. The pressure in 

 old plants is higher than in young ones, but falls as the plant becomes moribund. The author 

 concludes that a superior osmotic pressure is necessary for the formation of new growth but 

 is not necessary to maintain an organ after it has been formed. He points out the necessity 



BOTANICAL ABSTRACTS, VOL. Ill, NO. 3 



