1910] DISEASES OF PLANTS. 245 



tion of a form of Eucalyptus, which has been designatetl Eucalyptus marsdcni 

 n. sp., occurring in New Soutli "Wales. The appearance and structure of the 

 wood as well as the character of oil obtained from this species are also 

 described. 



The effect of lightning on Hevea, A. A. L., Rutgees (Arch. Riihbcrcult. Ncd- 

 erland. ItuUv, 3 (1919), No. 4, pp. 16.i-171, pU. 11). — A discussion, with illustra- 

 tions, of various types of Injury to Hevea rubber trees caused by lightning. 



DISEASES OF PLANTS. 



Ecological conditions of development of parasitic fungi, J. DtTFBfiNOY {Bui. 

 Trimcfit. Soc. Mycol. France. 34 (1918), No. 1-2, pp. 8-26).— Of the three sections 

 comprising this article, tlie first deals with altitude as related to tlie dis- 

 tribution of parasitic fungi, including such significant factcu'S as heat, light, 

 and moisture; the second with the virulence of rusts; and tlie third with such 

 biotic factors as the presence of other fungi and of insects. 



The Pyrenees offer no obstacle to the spread of fungus diseases, although 

 the study of disease fungi shows the existence of species adapted to mountain 

 regions, to plains, or to both. The principal factor determining specialization 

 appears to be insolation rather than temperature or liumidity. Mountain species 

 may be protected by strong coloration of the hosts or by that of their own 

 spores, the less strongly pigmented species of lower levels not being able to 

 bear the more intense insolation at the greater altitudes. 



Some of the plant diseases that were especially serious this season, with 

 suggestions (loira /S7«. A'pt. 1918, pp. 28, 29). — Notes are given on a number of 

 plant diseases and suggestions are made for their control. It is stated tliat seed 

 treatment with formaldehyde did not prove fully adequate for the control of 

 wheat scab, l)ut it is thought that coupling this treatment with the avoidance 

 of the use of highly infected seed will prove practicable. Black chaff, another 

 wheat disease, is reported as quite prevalent, but it is thought from the record 

 of disease surveys that not nnich damage need be anticipated from this source. 



Cedar apple rust is said to have been abundant, seriously damaging Wealthy 

 apples, and the removal of red cedars near apple orchards is recommended. 



The late blight of potatoes was troublesome in the northeastern part of the 

 State, and for (lie control of this disease thorough spraying with Bordeaux 

 mixture is reconunendod. 



Plant disease survey and information service, H. H.. Whetzel (Rpt. N. Y, 

 State Food Sup. Com., 1911, pp. 44, 45). — The leader of this service reports that 

 in addition to other work done, over .^OO specimens of diseased plants have been 

 examined. 



Prevention of insect pests and plant diseases (Rpt. N. T. State Food Com., 

 1918, pp. 108-110).- — This is a brief statement of the work, chiefly informational 

 and advisory, of the three experts on insect pests and plant diseases employed 

 to assist farmers and fruit growers, their work being confined mainly to 

 Wayne, Orange, and Cortland Counties. 



A quick method of eliminating seed-borne organisms of grain, I. E. Mel- 

 Hus and L. L. Rhodes (Science, n. ser., 50 (1919), No. 1279, p. 21). — From studies 

 made on account of the injury to seed treated with hot formaldehyde, the 

 authors have found that suspending the grain above the formaldehyde solution 

 for about 20 seconds destroyed all the fungi in or on the seed, as well as the 

 majority of the bacteria present. The formaldehyde solution used was 1 : 240, 

 and it was raised to a temperature of from 98 to 99° C. (208.4 to 210.2° F.). 

 The short treatment did not injure the germinating capacity of the seed, while 



