NOTES AND ABSTRACTS. 



*43 



or, if it is so due, such toxins are not affected by heat. As regards soils extracted 

 after treatment with toluene, large increases in the number of bacteria are found, 

 but these increases the authors attribute not to a destruction of toxins by the 

 antiseptic, but to the liberation by this treatment of soluble organic compounds. 

 That lack of food substances must be a main factor in determining the bacterial 

 increase is established by further experiments in which minute quantities of 

 nitrogen in the form of peptone were added to the extract, with the result that 

 there were very large increases in bacterial content. Another set of experiments, 

 in which Bacillus fluorescens liquefaciens was substituted for the species used 

 in the Australian experiments, showed at the end of seventy-two hours a very 

 large increase of cells in all four cases, i.e. (1) untreated extract, (2) heated 

 extract, (3) extract of toluened soil, (4) heated extract + peptone ; so that 

 the type of result obtained in this method of experimenting depends on the test 

 organism employed, and the general conclusion at which the authors arrive is 

 that there is no evidence to show that bacterio-toxins are likely to possess 

 importance in the partial sterilization of soils. — /. E. W. E. H. 



Beans, Varieties of, susceptible to Mosaic. By D. Reddick and V. B. Stewart 

 (Phytopathology,, viii. pp. 530-534, Oct. 1918). — The mosaic disease of beans is 

 prevalent on many varieties and in many districts in the States. It appears 

 to be transmissible through the seed, and apparently pollen from infected plants 

 may transfer the disease to seeds produced by apparently healthy plants. If 

 this be so the saving of seed from healthy plants will not alone prevent the 

 continuance of the disease ; the early elimination of affected plants from the 

 seed beds must also be effected. There is evidence that resistant strains of 

 some varieties exist. The disease results in the production of very small crops, 

 and at times of none. — F. J. C. 



Berberis aggregata Schneider. By T. A. Sprague (Bot. Mag. t. 8722 ; 

 August 1917). — A native of Western China, perfectly hardy. It possesses the 

 merit of being ornamental both when in flower and in fruit and is easily propa- 

 gated by seed. Flowers pale yellow, fruits crimson and orange. — L. C. E. 



Berberis candidula. By A. O. (Irish Gard. xiii. p. 153, Oct. 1918). — This 

 is a new Chinese Barberry with dark green glossy leaves, attractive yellow 

 flowers, and plum purple fruits. It is of low growing habit and suitable for 

 the rock garden. It is by some known as a variety of Berberis Wallichiana, 

 but is sufficiently distinct for ranking as a species. — E. T. E. 



Berberis Stapfiana Schneider. By J. Hutchinson (Bot. Mag. t. 8701 ; March 

 191 7). — Native of China, one of the Wilsonae type. The abundant seeds render 

 its propagation easy. Fruit crimson, attaining its greatest beauty in October 

 and November, later perhaps than any other Barberry. — L. C. E, 



Brown Rot of Apples. By H. Wormald, M.Sc. (Jour. Bd. Agr. xxv. 

 No. 3, June 1918). — An illustrated description of a disease which attacks 

 apple trees, and produces on the fruit brown areas which gradually increase in 

 size till the whole apple is infected. Small pustular swellings appear beneath 

 the skin and burst through as yellowish, powdery outgrowths, usually in con- 

 centric circles. The diseased apples shrink in size, and skin becomes wrinkled. 

 Under certain conditions which are not yet understood, stored apples affected 

 by this disease turn black, the skin remaining smooth and bearing few or no 

 pustules. 



Diseased apples are a source of infection to other apples. The spores are 

 carried by the wind and also by insects, and gain an entrance through cracks 

 and injuries, producing the characteristic symptoms of " brown rot." Such 

 apples may either fall to the ground or remain on the trees throughout the winter, 

 becoming " mummied " apples. The autumn-formed spores either die or are 

 washed away, but a fresh crop is developed the following summer and these infect 

 the young fruit. On certain soft-wooded varieties (e.g. ' Lord Derby ' and 

 ' James Grieve ') disease may extend through stalk of infected apple and enter 

 fruiting spur and branch, causing a canker round the base of the spur. The 

 disease can be controlled by removing diseased fruits and cutting away infected 

 spurs. — G. C. G. 



Bulbophyllum lilacinum Ridl. By R. A. Rolfe (Bot. Mag. t. 8723 ; August 

 191 7). — A native of the Malay Peninsula and Siam. A distinct and attractive 

 species, easily grown under tropical conditions. Flowers small, lilac with 

 purple blotches. — L. C. E. 



Campanula Ephesia Boiss. By N. E. Brown (Bot. Mag. t. 8715 ; June 

 191 7). — A native of Asia Minor. A handsome Campanula for the cool green- 



