NOTES AND ABSTRACTS. 



277 



Crataegus, New Arborescent. By J. Dunbar (Gard. Chron., 

 p. 114 ; Feb. 22, 1913 ; fig.). — Thirteen species of the Crus-Galli 

 group described. — E. A. B. 



Creosote, The Absorption of, by the Cell-walls of Wood. By 



Clyde H. Teesdale (U.S.A. Dep. Agr., For. Serv., Circ. 200; Sept. 14, 

 1912). — This gives the results of numerous experiments that have been 

 carried out at the Yale Forest School Laboratory. 



If the cell-walls absorb creosote, then a weakening effect similar 

 to that produced by moisture in the wood is brought about ; while, on 

 the other hand, should the cell-walls not absorb creosote, timber treated 

 by creosote should not suffer a decrease in strength, provided no 

 chemical reaction takes place. — A. D. W. 



Creosotes, Commercial : with Special Reference to Protection of 

 Wood from Decay. By Carlile P. Winslow (U.S.A. Dep. Agr., 

 For. Serv., Circ. 206 ; July 18, 1912). — An account of the various 

 creosotes, including that of coal tar, water-gas tar, wood tar, and 

 mixed coal tar. 



Coal tar creosotes rank higher in value for the treatment of timber 

 than that obtained from wood. — A. D. W. 



Crown Galls on Sugar Beet, Etiology of. By E. F. Smith 

 (Phytopathology, ii. pp. 270-272 ; Dec. 1912). — Spisar, in the Zeitschrift 

 fur Zucker Industrie in Bohrnen, claims that the crown galls of the 

 sugar beet are due merely to callus formation following wounding. 

 Dr. Smith here combats the statement, upholding the bacterial origin 

 of the galls. — F. J. C. 



Damping-off of Coniferous Seedlings, Use of Soil Fungicides to 



Prevent. By C. Hartley (Proc. Soc. Amer. Foresters, vii. 

 pp. 96-99 ; March 1912). — The author found that watering with a 

 dilute solution of sulphuric acid (■£$ fluid ounce to each square foot) 

 destroyed the damping-off fungus, Pythium Debaryanum, and weeds, 

 resulting in a greater percentage of germination, less loss of seedlings , 

 and the destruction of weeds. Care had to be taken to water the 

 beds thoroughly during growth. The nursery was of very sandy 

 soil and the method would probably not be applicable to calcareous 

 soils. The seedlings were those of Pinus divaricata. — F. J. C. 



Daphnes and their Cultivation. By Henry Correvon (Garden, 

 p. 104, March 2, 1913). — Though not all of easy cultivation, their very 

 ornamental flowers, tufted growth, but above all their delicious per- 

 fume place the Daphnes in the first rank of rock plants. The different 

 species or varieties are grown in gardens under all sorts of different 

 names ; e.g. D. collina has been found under six different names, D. 

 cneorum under three or four. The following is a short review of the 

 Daphnes in cultivation : 



D. alpina, 1 to 3 feet, white ; slightly-scented flowers, grows in 

 calcareous rocks of the Alps or Pyrenees in full sunshine. 



