358 EXPERIMENT STATION RECORD. 



through the thin membrane. This disease is not common, having been 

 observed but once by the author in a field of German millet. 



Leaf .smut of timothy^ redtoj), and hhie grass (pp. 348, 349). — The 

 author reports the common occurrence in timothy, redtop, and some- 

 times on blue grass of U. strmformis. It is generally found in the late 

 spring or early summer occurring on the leaves, sheaves, and rarely in 

 the inflorescence. Affected plants are smaller than healthy ones and 

 often, especially in the case of blue grass, are so inconspicuous as to be 

 easily overlooked. The fungus is not uncommon and frequently said 

 to do considerable damage, one estimate placing a loss of 30 per cent 

 due to its presence. 



Variations in the amount of leaf curl of the peach in the light 

 of weather conditions, A. D. Selby {Pfoc Soc. Prom. Agr. Sci. 

 lSOO,j>p. OS-lOJf). — In continuation of his observations upon the leaf 

 curl of the peach {Exoascus deformans) (E. S. R., 10, p. 557), the 

 author gives an account of a study of the relationship between the 

 weather conditions in the spring of the year and the amount of leaf 

 curl. The data cover the seasons from 1893 to 1899. The author con- 

 cludes that in northern Ohio the April weather is very largely respon- 

 sibU^ for the serious outbreaks of leaf curl. It is not prevalent there 

 to a damaging extent except in years with cool, vain}^ and cloudy 

 weather. It is believed that the profitable spraying for leaf curl may 

 bo predicted with fair certaint}' from the temperature and rainfall of 

 the first half of April. 



A parasite of carnation rust, F. H. Blodgett {Neic Yorh State 

 Sta. Bui. 175., _[)j). IS, pU. 3). — The occurrence of a fungus parasite of 

 carnation rust in several greenhouses in New York is reported. While 

 not naturally ver}^ effective as a check, by the use of artificial cultures 

 or inoculations the author believes that some benefit might be derived 

 from its presence. 



The parasite, which has been determined 2iS Darlucaflum . is described 

 at some length. Its presence is best determined by microscopic exami- 

 nation. The same fungus is said to infest the rust of asparagus, and 

 it is suggested that by growing garden asparagus in houses a sufficient 

 abundance of fungus might be obtained to check the ravages of the 

 rust on the carnation. 



Plasmodiophora brassicae, S. Nawaschin {Flora., 86 (1899)., pp. 

 404--4^7, pi. 1; ahs. in Jour. Roy. Micros. Soc. [London]., 1900, No. ^, 

 2). 239). — A series of observations on the minute structure of this par- 

 asite and on the changes which it undergoes during its intercellular 

 life are reported. In the amoeba stage it exhibits a decidedly abnormal 

 kind of indirect division, while in the spore-forming plasmodium the 

 division of the nucleus is of a typical karyokinetic character. The 

 differentiated group of infected parenchymatous cells of the host arise 

 by repeated division of the cells first infected. In the course of the 



