DISEASES OF PLANTS. 383 



55 (1904), No. 2, pp. 44-48; qbs. in Bot. Centbl., 95 (1904), No. 21, pp. 569, 570).— 

 The leaf-cast fungus of the common pine is shown by inoculation experiments to be 

 able to infect Pinus cembra. Under natural conditions the disease is transferred to 

 the young needles when growing in moist shaded regions, and especially when the 

 branches are near the ground. This last factor is due, in the author's opinion, to the 

 fact that the fruiting of the fungus takes place on the fallen leaves. By the extensive 

 shedding of its leaves the tree becomes greatly weakened and often killed. 



In appearance the disease resembles that of the common pine except that the leaves 

 infected in the spring of the year fall that autumn instead of being carried over until 

 the following spring. The fungus, Lophodi rmium pinaslri, is described at some length. 



The nutrition of diseased trees with the object of curing thern and destroy- 

 ing their parasites, I. J. Sheviryev (Selsk. Khoz. i Lyesov., 1903; abs. in Zhur. 

 Opuitn. Agron. [Jour. Expt. Landw.'], 5 (1904), No. 1, pp. 104-106).— The author 

 describes the results of 10 years' experiments in elaborating a method for artificially 

 introducing into the living plant foreign bodies in desired quantity, which while not 

 destroying the life of the plant may be of value in protecting it against parasites. 



According to the author, the investigations described are based on the following 

 facts: After the spring movement of the sap, when the pressure inside the vessels is 

 greater than that of the atmosphere, there follows in summer and fall a period of 

 negative pressure. If the vessels at this time are brought into communication with 

 the liquid, the latter enters and fills them under the pressure of the outside air. For 

 the successful introduction of liquids into the vessels of the tree it was found neces- 

 sary to prevent the entrance of air. The author attributes the failure of many 

 experiments in impregnating live trees with solutions to the disregarding of this fact. 



In order to exclude the air the vessels are opened under a layer of liquid. For 

 this purpose, if the trees do not exceed 3.5 in. in diameter, their trunks are sur- 

 rounded by a feeding funnel of aluminum fastened to the tree by means of cement. 

 For larger trees only portions of funnels are fastened to the trunk. After the funnel 

 is fixed in place the solution is poured in and a cut made below the level of the 

 liquid through the thickness of the bark and part of the sapwood. The liquid at 

 once begins to be sucked in and to diffuse above and below the cut. A Mariotte 

 vessel provides for the automatic replenishing of the liquid as it is absorbed. 



The absorption of the liquid continues at the initial velocity for some time, after 

 which it slackens, being influenced by climate, season of year, and state of the 

 weather. The absorption takes place most rapidly in dry air at high temperatures 

 and in strong sunlight. The absorption continues for about 5 days, and the immediate 

 cause of its cessation seems to be the choking up of the vessels through which the 

 liquid enters the tree. This is shown by the vigorous renewal of absorption through 

 new cuts made in the tree. In an experiment on an oak tree 7 in. in diameter 11.37 

 gal. of liquid was absorbed by the tree in 53 hours. 



Experiments with a number of solutions colored with eosin or methyl blue showed 

 that liquids diffuse both upward and downward and also horizontally. The diffusion 

 in a horizontal direction seems to be along the rays, as the heartwood does not become 

 colored. The colored liquid has been traced to the smallest branches and also to the 

 leaves, and in the case of experiments with grapevines into the berries themselves. 

 The diffusion into the roots does not seem as uniform as through the sapwood of the 

 trunk. 



The author has not made much progress in finding substances which may be intro- 

 duced in sufficient quantity to be destructive to parasites without being injurious to 

 the plant, but expects interesting results from experiments with certain barium com- 

 pounds with which he is experimenting. — p. fireman*. 



A coral-spot disease of various trees and shrubs (Jour. Bd. Agr. [London], 

 11 (1904) , No. 4, pp. 202, 203, pi. 1). — A description is given of a disease which attacks 



