DISEASES OF PLANTS. 59 



trees that has been nndcr investigation since ISOS. The general el laract eristics are 

 those exhil)ite(l in an attack of Moirilla cinerea on the cherry, bnt the fungus seems 

 quite distinct. Subsequent studies sliowed that the disease was caused l)y an unde- 

 scribed spefcies of Fusariuni, to which the author has given the name Fumrium 

 gemrniperdd, n. sp. Inoculation experiments are reported which seem to establish 

 the i^arasitism of the fungus, and the author points out the apparent relationship that 

 exists between the amount of rainfall during the period of flowering and the destruc- 

 tiveness of the disease. In 1899 there were but 2 days lietween April 15 and May 15 

 on which no rain fell, and the disease proved very destructive, while in 1900, with 

 only 13 rainy days and about one-fourth the rainfall of the previous year, the disease 

 did little damage. It is believed that during the years of normal rainfall this 

 disease will not prove troublesome. 



A disease of plums and cherries, M. C. Cooke {Jour. Roy. ITort. Soc. [London], 

 26 {I'jol), Xo. ..'-J, jqi. ('XLII, CXLIII). — The author reports examining the plum, 

 cherry, and other orchard trees, in which he found a white mj'celium growing between 

 the bark and tlie wood, ultimately destroying the tree. This is ])resumed to be the 

 mycelium of some agaric, proba))ly growing in the vicinity of the tree. No fruiting 

 organs having l)een observed, it was imj)Ossil)le to determine the species, Ijut C'oUi/hia 

 fnsipes was growing near by, and it is thought to ])e probal)ly the cause of the 

 disease. 



Cherry diseases, W. Carrutiiers {Jour. Hoy. Ayr. Soc. EnglamJ, (I? {1901), pp. 

 241-^47 , figs. 7). — An account is given of a leaf disease of cherry, due to (<'nonnynia 

 erythrostoma. This disease has been previously noted (E. S. R., 13, p. 567). In addi- 

 tion to the foregoing, an attack of Cladoaporium epiphylJuin upon cherries is noted. This 

 fungus causes small brown specks upon the fruit, and while the growth a;)pears to 

 be entirely superficial the development of the fruit under the spots is arrested. The 

 fungus also grows on the dead leaves which are quite prevalent as a result of attacks 

 of the disease first described. A third disease, due to Exoascus cerasi, which pro- 

 duces distorted branches on the cherry tree, known popularly as witches' brooms, is 

 dei^scribed. Miscellaneous notes are given on a number of other plant diseases, the 

 ])rint'ipal of which are due to attacks of Botrytis parasitica and Sclerotinia sclerotiorum. 



Silver leaf, M. C. Cooke {./oar. Hoy. Hort. Soc. [Londori], 26 {1901), No. 2-3, 

 pp. CA'A'A'TT, CXXXVII). — The author states that there is no essential relation 

 between gumming and the so-called silver-leaf disease of peaches, plums, etc. He 

 suggests that the silver leaf is i)ossi))ly a modification of the disease known in the 

 United States as peach yellows and recommends that the treatment here em})loyed 

 for the eradication of peach yellows be adopted for the prevention of the spread of 

 silver leaf. 



Silver leaf {.Tour. Ruy. Hort. Soc. [London], 26 {1901), Xo. 1, p. 252) .—Th\^ dis- 

 ease is said to attack all species of the Prunus tribe, being particularly troul)lesome 

 to peaches and plums. It is called silver leaf because of the silvery or ashen appear- 

 ance of the surface of the leaf, which seems to be due to a separation which takes 

 place between the outer skin of the leaf and its inner substance and a thin film of 

 air separating them. What causes tlie separation is as yet unknown. It attacks trees 

 in apparently robust health, spreading from twig to twig until at last it destroys the 

 entire tree. At present the only means for preventing the spread of the disease is 

 the complete destruction of trees which are affected. 



A disease of the black locust, H. vox Schrenk {Rpt. Missouri Boi. Gardens, 12 

 {1901), pp. 21-31, pis. 3). — Detailed descriptions are given of a disease of black 

 locust {Rohinia pseudacacia) , which is caused by the fungus Polyporus rimosus. A 

 preliminary note of this disease has already been given (E. S. R., 13, p. 154). 



The Botrytis disease of coniferous seedlings, J. Tuzsox {Ztschr. PflanzenkranJc., 

 11 {1901), No. 2-3, pp. 95-98). — A description is given of the attacks of Botrytis 

 cinerea on spruce and larch seedlings, and comparisons are drawn between that spe- 



