NOTES AND ABSTRACTS. 



759 



Cabbage Rot : Vitality of the Cabbage Black Rot Germ on 

 Cabbage Seed. By H. A. Harding, F. C. Stewart, and M. J. Prucha 

 (U.S.A. Agr. Exp. Stn. Geneva, Bull. No. 251, Oct. 1904; 1 plate).— 

 Black rot of Cabbage is a destructive bacterial disease caused by Pseudo- 

 monas campestris (Smith). No satisfactory method of controlling the 

 disease in the field has yet been found. Concerning the ability of the 

 disease germs to survive the winter on the seed, there has been a difference 

 of opinion. Investigations on this point are the subject of the present 

 bulletin. 



The conclusion is that much of the Cabbage seed on the market is 

 contaminated with germs of the black-rot disease, and some of these may 

 survive the winter and become a source of infection to young Cabbage 

 plants. 



As a preliminary measure, it is advised that all Cabbage seed be dis- 

 infected before sowing by soaking for fifteen minutes in a 1-1,000 

 corrosive sublimate solution, or in formalin, one pound to thirty gallons 

 It is not expected that this treatment will prevent either leaf or roou 

 infection in infected soils ; but it may be safely relied on to prevent all 

 danger from infected seed. It will not injure the germination. 



The disease, it is contended, made its appearance in England in 1903 

 on the Swede Turnip. — M. C. C. 



Cabbage Tribe, History of the. By Georges Gilbauth (Rev. Hort. 

 pp.90-93,Feb. 16, 1905 ; pp. 187-189, April 16, 1904 ; pp. 238-240, May 16, 

 1904). — An interesting series of articles, with some woodcuts. — G. T. D. 



Calamitean Root, The Papillae on the Epidermoidal Layer 

 of the. By Grace Wigglesworth (Ann. Bot. xviii. October 1904, 

 pp. 645-648 ; 3 figs.). — The authoress suggests that the fibrous fragments 

 which project into the cells of the epidermoidal layer of Calamitean roots 

 represent the short arrested branches of a fungus mycelium. The sug- 

 gestion is based on similar appearances observed in recent plants. 



A. D. C. 



Calanthe discolor. By R. A. Rolfe (Orch. Rev. vol. xii. p. 131). — 

 Particulars of this supposed hardy Japanese Orchid are given. Doubts 

 are thrown upon the possibility of its standing our winters unprotected. 



H. J. C. 



Calceolarias, Hardy. By S. Arnott (Gard. Mag. 2668, p. 1835, 

 17/12/04). — Six species are described in this article under the heading of 

 Hardy Calceolarias, but the term " hardy" cannot really be applied to any 

 of the species of Calceolaria, if the term "hardiness" be understood to 

 mean full exposure. 



The so-called hardy species are stated to be C. plantaginea, Kellyana, 

 violacea, pinnata, alba, and andina. None of these are truly hardy at 

 Kew, but perhaps some of them may survive a mild winter in warmest 

 districts. 



An illustration of C. polyrrhiza is given. — W. G. 



Calcium Cyanamide. By A. D. Hall (Jour. Agr. Sc. vol. i. part L, 

 pp. 146-148 ; Jan. 1905). — A note on calcium cyanamide (CaCN 2 ). This 



