NOTES AND ABSTEACTS. 



361 



it is very difficult even for the expert to detect Bacterium tumefaciens 

 in situ. 



The author also points out that in all orchard or sugar-beet regions 

 in America the possible danger of crown gall infection through 

 leguminous crops must be considered. The use of soil for inoculat- 

 ing alfalfa on clover land, if selected at random may be a serious 

 menace to any succeeding sugar-beet crop or to land eventually to be 

 planted with orchard trees. He believes that besides alfalfa, crimson 

 clover, and alsike there is reason to suspect that all the clovers may 

 be susceptible to Bacterium tumefaciens. — I). M. C. 



Cycad Trunk, The Adult. By Charles J. Chamberlain {Bot. 

 Gaz. pp. 81-104, Aug. 1911. 20 figs.).— The author describes the 

 minute anatomy of Dioon (two species), Ceratozamia, and Zamia. 

 Growth rings are found in both species of Dioon, but only corre- 

 sponded to a period o'f activity in the formation of crowns or cones 

 in D. spinulosum-. The adult trunk of this species resembles (in 

 transverse section and histologically) that of Cycadeoidea. — G. F. S. E. 



Cyclamen, New. By Graf von Schwerin-Wendisch (Garten flora, 

 vol. Ixi., pt. v., pp. 119-120; 1 fig.)- — Cyclamen persicum Schwerinae, 

 a sport from G. persicum, has bell-shaped flowers; the petals rise 

 upright from the stalk, then suddenly bend down. The blooms may be 

 dark or bright pink or white, with red centres. — S. E. W. 



Cyppipedium bellatulum. By 0. Witt [Orchis, vol. vi., pt. ii., 



pp. 19-22 ; 1 plate). — To ensure success plant the newly imported 

 orchid in a mixture of potsherds and pieces of limestone. Spray 

 moderately. When new roots appear, remove any dead old roots 

 and re-pot in a mixture of Oypripedium compost and broken potsherds. 



S. E. W. 



Daphne retusa (Bot. Mag. t. 8130). — Western China. Family 

 Thymelaeaceae ; tribe Tkymelame. Shrub, 2-3| feet high, flowering 

 in spring with the leaves. Leaves lasting till second year, lJ-3 inches 

 long; flowers umbellate; perianth white tinged with rose or violet; 

 berry fleshy red, 5 lin. long. — G. H. 



Daphne X Thauma. By E. Farrer {Gard. Chron. p. 22; July 13, 

 1912; fig.). — An account of the discovery, and a description with Latin 

 diagnosis, of a hybrid between Daphne rupestris and D, striata. 



E. A. B. 



Davidia involucrata var. Vilmoriniana [Bot. Mag. t. 8432). 



C^eiiti-al and Western China. Family Cornaceae ; tribe Nysseae. Tree 

 of medium height, with linden-like foliage and capitate inflorescence 

 Nviih two large white bracts. Leaves 2^-4^ inches long; bracts- sessile, 

 usually unequal, white, oblanceolate ; perianth none; stamens 5-10 

 or more; anthers purple.— G. H. 



