744 EXPERIMENT STATION RECORD. 



in the open air, and the resulting infection tabulated for the months of 

 November, December, January, and March. It was found that the incubation 

 period was lengthened as the temperature fell until it reached a duration of 5 

 months. Plants inoculated on October 28, November 21, and December 18, and 

 kept in the open air did not produce uredosori until March 28 of the following 

 year. 



The author, therefore, believes it entirely possible for the uredospore mycelium 

 to winter over in the tissues of the host, without any external evidence, until 

 an optimum of temi)erature has been reached in the spring, when uredosori 

 will aijpear. A table is given showing the maximum, minimum, and average 

 temi^eratures and the frost periods for the mouths of October, November, and 

 December, 1908, and for January, February, and March, 1909. 



After discussing the possibility of direct teleutospore infection on the wheat, 

 and of infection by means of seed according to the myeoplasm theory of 

 Ericksson, the author concludes that no authentic experimental proofs of such 

 infection have yet been offered. 



Crown gall of plants, E. F. Smith (Phytopathology, 1 {1911), No. 1, pp. 

 1-11, pis. 2). — In a brief preliminary note on this disease the author claims 

 that there is no evidence to show that fungi, myxomycetes. mites, frost, and 

 nutrition disturbances iwoduce this disease, but that it is undoubtedly due to 

 bacteria {Bncterium tuniefaciens), as shown by inoculation experiments con- 

 ducted during the past 6 years. During this time successful inoculations were 

 obtained from pure cultures and subcultures on more than 1,000 plants. 



A bulletin containing details as to experiments, etc., is in prei)aration. 



Cedar apples and apples, F. E, Lloyd and C. S. Ridgway {Bui. Agr. Dept. 

 [Ala.] No. 39, 1911, pp. 19, figs. 12). — In a general discussion of the cedar apple 

 fungus, the authors claim that several crops of sporidia may be produced In a 

 given season, (1) by the germination of some teleutospores which failed to be- 

 come active when the sori swelled, (2) by the swelling of sori which were 

 immature at the time oC the first rains, or (3) by the secondary growth of a 

 sorus after it has once become gelatinous and then dried. In {he third case, the 

 part of the sorus exposed beyond the tissues of the gall swelled when wet by 

 rain, but the sorus was not comiiletely developed and continued to push out 

 from the gall, which with the next rain swelled and produced sporidia. 



The spei'mogonia (pycnia) were foand to secrete aud exude a large amount of 

 nectar which attracted bees and other insects, thereby disseminating the 

 pycnospores. It is also claimed that in dry weather the divisions of the pseudo- 

 peridium of the secidia are straight or bent outward, permitting the spores to 

 escape, but that when the atmosphere becomes moist these peridial strips curl 

 inward, closing the oldening of the iiecidial tube and preventing the escape of the 

 spores. Later, on drying, these strips are again straightened out, carrying 

 some of the secidiospores on their tips, thus setting them free. In a few in- 

 stances, fresh outgrowths from a point near the base of matured galls which 

 have just finished bearing sori may occur. These outgrowths remain alive and 

 form galls the succeeding year. 



A list is ai^i^ended of varieties of amiles which are resistant or susceptible to 

 this disease. 



A new fruit spot of apple, W. M. Scott {Phytopathology, 1 {1911), No. 1, pp. 

 32-34). — Attention is called to a fruit spot of apples, especially of the Jonathan 

 and Esopus varieties, which develops almost entirely after the fruit is picked 

 and while in temporary cellar storage, en route to market, or after removal 

 from cold storage. The spots, which are usually distributed promiscuously 

 over the surface of the ai">ple, are dark brown in color, usually circular in out- 

 line, from i to i- in. or less in diameter, and slightly sunken, with a lenticel 



