360 JOUKNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The wilt can be controlled by growing the disease-resistant varieties 

 now on the market, but root-knot can only be controlled by rotation 

 and the growing of crops resistant to eelworm. A list of such crops 

 is given; it includes barley, wheat, rice, winter oats, iron cowpea, &c. 

 The organization of a co-operative campaign is suggested to utilize all 

 existing agencies, and put wilt-control on a self-supporting basis, by 

 outlining methods of control, by providing sufficient seed of resistant 

 varieties, and furnishing all the information necessary to any farmers 

 or workers who might wish to keep up the standard of their stocks 

 by breeding and selection, &c. — D. M. C. 



Cotyledon SUbrigrida (Bot. Mag. t. 8445). — Mexico. Family 

 Crassulaceae. Herb, shortly stemmed, succulent. Leaves rosulate, 

 4-6 inches long, 2^ inches wide ; peduncles 1^ foot high ; sepals spread- 

 ing, glaucous; corolla |-inch long, 5-angled, brilliant orange above, 

 yellowish lower, glaucous. — G. H. 



CrasSUla Barklyi {Bot. Mag. t. 8421).— South Africa. Family 

 Crassulaceae. Succulent herb, 1-2 inches high. Leaves opposite, 

 imbricated, 2-3 lin. long; flowers terminal, capitate; corolla white, 

 lobes 3 lin. long. — G. H. 



Creosote after their Injection into Wood, Volatilization of 



various Fractions of. By 0. H. Teesdale {U.S.A. Dep. Agr., 

 Forest Service, Circ. 188 ; Oct. 17, 1911). — A valuable paper, inasmuch 

 as a knowledge of the volatilization of creosote from timber after 

 injection is of great importance. — A. D. W. 



Crotons. By F. Weber {Garten flora, vol. Ixi., pt. iv., pp. 86-90). 

 — To keep Crotons free from insect pests, spray with a solution of 

 dextrine (1 lb.) in 18 pints of warm water, to which 1 lb. of tobacco 

 extract is added. After three days spray well with water. — S. E. W. 



The Relation of Crown Gall to Leg-ume Inoculation. By 



K. F. Kellerman {U.S. Dep. Agr., Bur. PI. hid., Circ. 76).— This 

 circular draws attention to the fact that the micro-organism, Bacterium 

 tumefaciens, which Erwin F. Smith has so successfully investigated, 

 and which causes crown gall in orchard trees, tomatos, sugar-beet, j 

 roses, and various other plants, can also attack certain legumes, suchj 

 as alfalfa, red clover, and alsike. The bacterium causes nodules on 

 the roots not unlike those of the nitrogen fixing organism of Legumin- 

 osae, Pseudomonas radicicola, but on closer inspection it can be seen 

 that with Ps. radicicola the nodule is merely an outgrowth of thel 

 root, whereas the crown gall tumour causes considerable distortion! 

 and branching of the root, the rootlets springing from the gall 

 itself. The tissues of the tumour are white as distinguished from 

 the pinkish flesh of the leguminous nodule. 



Several laboratory tests are given for distinguishing these twc 

 organisms, one of the chief being that it is very easy to find innumer 

 able bacteria in the nodule ; while on the other hand in the crown gal 



