208 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Cannas, A Bacterial Disease of. By Mary K. Bryan {U.S.A. Jour. Agr. 
Res. xxi. No. 3, May 1921, pp. 143-152; 8 plates). — A hitherto undescribed 
bacterial disease of buds of Carina is caused by Bacterium cannae n. sp. It is 
primarily one of young tissues and moist conditions. Infection takes place 
through stomata and spreads through the parenchymatous intercellular spaces 
of the leaf blades, petioles, and stems. It is most destructive to young plants, 
and prevents the plants from blossoming. The method of wintering is unknown, 
and no special control measures are as yet suggested. 
The bacterium causing the disease is described. — A . B. 
Carbon Dioxide, Residual Effects of Carbon Dioxide Gas Additions to 
Soil on Roots of Lactuca sativa. By H. A. Noyes and J. H. Weghorst {Bot. 
Gaz. lxix. No. 4, April 1920, pp. 332-336 ; 5 figs.). — In a previous paper 
the writers showed that the " carbon dioxide content of garden soils is some- 
times detrimental to the root development of some of the plants growing in 
the garden." The authors' recent investigations show that the roots of the 
plants grown in the pots that had received the carbon dioxide applications the 
previous year (a lapse of nine months) had the malformations attributed to carbon 
dioxide in the previous year. Where the soil had never been subjected to 
treatment with this gas, the roots were well spread and extended considerably 
into the soil. Where it had been applied, the roots were shorter, spread out 
horizontally just beneath (o" to 2") the surface of the soil, and had tap roots 
that were abnormally short, crooked, and branching. The residual effects of the 
gas were greater for the continuous than the intermittent treatments. The roots 
of the plants where the 24-hour treatments of carbon dioxide had been given 
were more affected under the manure than the fertilizer treatments. — R. J. L. 
Castor-Oil Bean, Bacterial Wilt of. By Erwin F. Smith and G. H. God- 
frey (U.S.A. Jour. Agr. Res. xxi. No. 4, May 1921, pp. 255-262; 13 plates). 
— The bacterial wilt of the Castor-Oil Bean (Ricinus communis L.) was first noticed 
in 1 91 8, and was found to occur in many parts of Florida and South Georgia. 
It causes a wilting of the leaves and growing points, and may come slowly or 
quickly, and bacterial exudates from the vascular bundles may be noticed. 
The organism isolated was found to be Bacterium solanacearum, and these when 
inoculated into tomato plants soon caused wilting to take place. Young Ricinus 
plants were also inoculated successfully. 
The organism is found to attack Tropaeolum majus L., Vanilla planiflora 
(Andrews), Sunflower (Helianthus annuus L.), Common Balsam (Impatiens 
balsamina L.), and Fuchsias. — A. B. 
Celery, A Bacterial Leafspot of. By Ivan C. Jagger (U.S.A. Jour. Agr. 
Res. xxi. No. 3, May 1921, pp. 185-188 ; 2 plates). — A hitherto undescribed 
bacterial disease on leaves of celery has been under observation since 1910. It 
causes spots of a rusty brown colour, somewhat resembling the Septorialeaf spots, 
and is apparently confined to the leaf blades. Bacteria have been repeatedly 
isolated and characteristic spots reproduced by inoculation with pure cultures. 
It has one to three polar flagella, forms colonies on nutrient agar, greyish white, 
shiny, and circular, forms acid with glucose and saccharose, alkali from lactose and 
glycerine, no nitrate reduction, no diastatic action. Is parasitic on leaves of 
celery (Apium graveolens L.). The author names it Pseudomonas apii n. sp. 
A.B. 
Cherry Growing in New South Wales. By W. J. Allen and S. A. Hogg 
(Agr. Gaz. N.S.W. xxxi. pp. 277-279). — The cultivation of cherries can only 
be carried on successfully in the highlands of New South Wales, as the trees 
dislike a high temperature and cannot resist drought. The trees are planted 
20-24 * ee t apart in well-drained loam overlying sand or rubble. Black tares, 
sown in winter and ploughed under in spring, form a useful fertilizer. The 
favourite variety for canning is ' Florence.' — S. E. W. 
Citrus-Canker in Soil. By H. A. Lee (U.S. Jour. Agr. Res. vol. xix. No. 5, 
June 1920, pp. 189-206 ; 2 plates). 
Citrus Canker Organisms in Soil, The Decline of the. By H. R. Fulton (U.S. 
Jour. Agr. Res. vol. xix. No. 5, June 1920, pp. 207-224). 
It is a commonly accepted idea amongst fruit-growers that the citrus canker 
organism (Pseudomonascitri Hasse) lives and multiplies in the soil. The presence or 
absence of the organism in the soil is an important one in three aspects : (1) If 
organism is able to live actively, that is, increase and multiply ; (2) whether 
it exists passively ; or (3) whether it is killed in the soil. The first author shows 
that the organism disappears from unsterilized soil in tubes and boxes within 
six days after inoculation. In sterilized soil, however, inoculated with P. citri, 
