DISEASES OF PLANTS. 139 



is often confused, with the early blight. Increasing the vigor of the 

 plant and irrigation wherever possible will prevent tip burn to a great 

 degree. 



On the primary cause of potato scab, B. Roze {Compt. Rend., 

 122 {1896), Ifo. 18, pp. 1012-1011).— From studies made upon pot cultures 

 in which sound tubers were exposed to scabby ones the author is led to 

 believe that the primary cause of the scab is bacterial, and the organism 

 is called Micrococcus pellucidiis. It is nearly spherical, about 0.6 // in 

 diameter, and is said to be very active. It is thought to prepare the 

 way for Oospora scabies or other organisms which live for a time at least 

 as saprophytes upon the tissues destroyed by the Micrococcus. 



A new disease of almond trees, U. Beizi {Ztsclir. Pflanzenlcranlc, 

 6 {1896), Ifo. 2, pp. 65-72, pi. 1). — The author describes an anthracnose 

 of almonds which has appeared in Sardinia, the first specimens having 

 been received from Cagliari in April, 1805. The disease is said to be 

 caused by a new species of Gloeosporium, to which the name G. amyg- 

 dalinum has been given. The fungus is fully described, aud numerous 

 notes are given relating to its biology. 



The fungus is said to attack the young fruit, although it rarely occurs 

 upon the branches. The early indication of its presence is the appear- 

 ance upon the green fruits of yellowish spots surrounded by concentric 

 rings of lighter color. Later it appears as a gray rot. From the action 

 of copper solutions upon the spores the author thinks that Bordeaux 

 mixture will probably prove efficient in combating the disease. 



Frost injuries to apples and pears, L. R. Jones ( Vermont Sta. Bui. 

 49, p. 100, fig. 1). — Notes are given of a serious russeting of apples and 

 pears, due to a late frost in 1895. The cause was attributed by many 

 growers to injury from spraying, but investigation showed that sprayed 

 and uusprayed trees suffered alike. The author reports having 

 observed the same injury upon fruit in Canada, New York, and 

 Wisconsin. 



On the browning of grape cuttings, P. Vial A and L. Eavaz 

 {Compt. Rend., 122 {1896), No. 20, pi). 1112-1144).— "IhQ common brown- 

 ing of grape cuttings, which is due to bacteria aud has been considered 

 as a disease, is said by the authors to be without any pathological 

 effect. Externally the cuttings retain their normal color and when 

 grafted readily unite with the stock. They root well and produce vigor- 

 ous branches. The bacteria are never found in the new growth no 

 matter how abundant they may have been in the cutting, nor do they 

 descend into the stock in case of grafting. 



Experiments for the prevention of plum leaf spot and cherry 

 leaf spot and fruit rot, S. A. Beach {Neiv Yorh State Sta. Bui. 98, 

 11. ser.,pp. 17, pis. 5, fig. 2).— Experiments were conducted during 1895 to 

 determine the relative values of an eau celeste soap mixture and Bor- 

 deaux mixture for preventing leaf spot of plums {Gyli^ulrosporium 

 padi). While investigating the merits of the two fungicides the times 



