550 EJtPERIMENT STATION RECORD. 



been scorched by Are. As the needles of the white pine fall after 2 years, in 

 case the newer ones are affected the trees become more or less defoliated. 



This disease is now widely distribnted throughout the central and southern 

 parts of New England and occurs also in New York. New Jersey, and Penn- 

 sylvania. It has thus far caused but little damage, but if it proves to be in- 

 fectious it may produce serious results. The cause of the trouble is unknown. 



The blight on chestnut trees, J. Mickleborough {Conservation. IJ/ (/.90.S), 

 No. 11, pp. 58->-5SS, figs. 2). — An account of the occurrence and distribution of 

 the blight of chestnut trees due to the fungus Diaporthe parasitica. The fungus 

 has already caused the destruction of nearly all the chestnut trees in Prospect 

 Park, Brooklyn, and is spreading rapidly in a number of other localities. 



Extent and importance of the chestnut bark disease, E. R. HonsoN ( U. /S. 

 Dept. Agr., Forest Scrv. [PampliJct], IDOS, Oct. 21, pp. 8). — A description is 

 given of the chestnut bark disease due to Diaporthe parasitica, or Valsonectrin 

 parasitica, as it is sometimes called, previous accounts of which have been given 

 (E. S. R., 19. pp. 2m. 1051, 1154). 



A disease of the Cineraria, F. J. Chittenden {Jour. Roy. Hort. 8oe. \ Lon- 

 don], 33 {1908), Xo. 2, pp. 511-513, figs. 2). — A report is given of a disease of 

 Cineraria leaves, due to the fungus CoJeosporiinn senecionis, which, in view of 

 the fact that the fungus occurs on a large number of weeds, may prove quite 

 troublesome. 



Upon the Cineraria the attack is characterized by the appearance on the 

 under surface of the leaves of orange-yellow, waxy-looking patches, covering 

 areas varying from 0.25 in. in diameter to almost the whole surface of tlie leaf. 

 As the disease spreads, tlie upper surface of the leaves becomes blackish in 

 color. The yellow patches appear in September, and the yellow color is due to 

 uredospores. Later these patches become red and bear the winter spores. 



The injury to the plant arises from the fact that considerable nourishment 

 is withdrawn by the fungus, and the plant also suffers by the disfiguring of the 

 leaves. 



The attacks of the fungus may be prevented by spraying with a solution of 

 permanganate of potash. 



The occurrence of Rhodochytrium spilanthidis in North America, G. F. 

 Atkinson {Bot. Gaz., JfU {1!)U8), No. //, pp. 21)9-301; Science, n. ser., 28 {1908), 

 No. 121t, pp. 691, 692). — The occurrence of the parasitic alga R. spilanthidis 

 on the leaves of the ragweed {Ambrosia artemisi(rfolia) in North Carolina is 

 reported. 



The parasite is an alga devoid of chlorophyll, and attacks the leaves, stems, 

 pedicels, flower bracts, and other parts of the host plant. It begins its develop- 

 ment in early summer on the small seedlings and by succeeding crops of 

 zoospores continues the infection of these plants throughout the season, until 

 finally the flowet* racemes are affected. The parasite has a reddish yellow oil 

 deposited in the protoplasm, and this is so massed in the larger sporangia that 

 it causes a bright red color visible through the thin layer of the cortical tissue. 

 The plant is always located in or adjacent to the vascular bundles, and there 

 is an extensive system of mycelial rhizoids which are profusely branched. 



This parasite was first discovered in North Carolina by Dr. F. L. Stevens, who 

 referred material to the author. Since the first collection was made in August, 

 1903, it has occurred in abundance every year, and 14 additional stations were 

 reported in 1908. In many cases the ragweed is so affected that the destruction 

 can be recognized from car windows. 



Bordeaux mixture and other fung'icides, G. Quinn {Jour. Dept. Agr. So. 

 Aust., 12 (1908), No, 2, pp. I'fU-lVJ), — Formulas are given for the preparation 



