5l8 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
peach (P. persica), and the plum (P. domestica, P. americana, Sec.) are all attacked 
by a bacterial disease which causes " shot-hole " leaves and " black-spot " fruit, 
as well as cankers on the branches of these trees. The disease is of American 
origin and is only known in the United States. It causes extensive damage in 
the more humid districts of the South. 
The common fungus disease of plum and apricot foliage (Cylindrosporium 
Padi) shows similar symptoms to this bacterial leaf-spot disease, but can be 
readily distinguished from it by forming a white downy growth on the lower 
surface of the spot. 
The bacterium was first described by Smith and named Pseudomonas Pruni, 
but later this name was altered to Bacterium Pruni. Conclusive proof of the 
pathogenic nature of the organism was obtained by Dr. E. F. Smith by inocu- 
lating the foliage and fruit of the plum ' Abundance.' The author repeated and 
confirmed this on the plum, and extended the infection experiments to the 
apricot, nectarine, and peach. Details are given of the behaviour of the bacterium 
in various cultural media. Experiments were made to determine the suscepti- 
bility of different varieties of the various hosts to the disease. 
The chief hope of control lies in the production of resistant varieties of trees 
by careful selection and crossing. — A. B. 
Storage Rots, Temperature Relations of some Fungi causing. By A. Ames 
{Phytopathology, v. pp. 11-21, Feb. 1915). — A series of experiments was under- 
taken to ascertain the temperature at which germination, growth, and death 
occurred in the rot-producing fungi mentioned below. All are common on 
various fruits in store, but the author found that different strains of a species 
differed somewhat in their temperature relations. At i-2°C. Thielaviopsis 
etheceticus, Monilia fructigena, Rhizopus nigricans, Glomerella rufomaculans, and 
Cephalothecium roseum made no growth, while Penicillium glaucum formed a 
few small colonies in a few cultures, and at about i5°C. most formed fruits 
within a few days, though Thielaviopsis etheceticus and Glomerella rufomaculans 
reached their maximum growth at 3o°C., and Rhizopus nigricans at 36°C. The 
thermal death-point in the case of Thielaviopsis etheceticus, Monilia fructigena, 
and Glomerella rufomaculans lay between 52 0 and 54 0 , of Cephalothecium roseum 
between 47 0 and 48 0 , and of Rhizopus nigricans between 6o° and 6o*5°C. 
F. /. C. 
Storm and Drouth Injury to Foliage of Ornamental Trees. By C. Hartley 
and T. C. Merrill (Phytopathology, v. pp. 20-29, Feb. 1915). — The appearance 
of foliage of maple and other trees damaged by drought and storm is described. 
The similarity of the damage produced by these two causes is remarked upon, 
for in both cases the death of tissue is usually confined to the leaf -margins, 
although in storm damage the tissues between the nerves may also be affected. 
Inspection of the whole tree and knowledge of previous weather conditions 
appear both to be necessary in order to differentiate positively between the two 
types. — F. J. C. 
Strawberries, Diseases of, by Species of Botrytis and Rhizopus. By N. E. 
Stevens (Jour. Agr. Res. vol. vi. No. 10, June 1916, pp. 361-366; 2 plates). — The 
fungi causing rots in strawberries in transit are chiefly Botrytis (cinerea ?) and 
Rhizopus (nigricans ?). The berries attacked by the first show a characteristic 
dry-rot ; they retain their shape, shrivel somewhat, and no leaking of juice is 
evident ; whereas the berries attacked by Rhizopus quickly decay with the 
loss of a large volume of juice. 
The author finds that this difference is due to the fact that the Botrytis 
penetrates all parts of the berry, growing within the cells as well as between 
them, and ramifies through the tissues, filling them with a network of mycelium. 
On the other hand, the Rhizopus is found only on the outer portion of the berry. 
The hyphas grow between the cells, destroying the middle lamellae so that the 
cells separate and quickly decay. — A. B. 
Strawberry « Madame Moutot.' By J. Blanchouin (Le Jard. vol. xxx. pp.29, 
30). — Although ' Madame Moutot ' is a robust grower, thriving in any ordinary 
soil and bearing very large fruit, it is not recommended for cultivation, as the 
flavour is only second-rate and the colour unattractive. In wet seasons it soon 
decays. — S. E. W. 
Strawberry Stock Experiments. By B. T. P. Barker (Ann. Rep. Agr. 
Res. Stn., Long Ashton, 1915, p. 100). — Strawberry plants of the same variety 
were obtained from twelve different nurseries in various parts of the country. 
