912 



SCIENCE 



[N. S. Vol. XXIX. No. 753 



The parasitism of a fungus of the genus Piricu- 

 laria, announced before this section in 1906, and 

 since confirmed by Fulton, has been verified by 

 over six hundred inoculations. The parasite is a 

 vera causa, although the occurrence of blast is 

 enormously favored by a soil rich in nitrogen. 

 It is doubtful whether a specific designation of 

 the fungus can be made without revising the 

 genus. The speaker's investigations in Italy in 

 1908 indicated the identity of blast with brusone, 

 and tended to confirm the views of Farneti on the 

 etiology of the disease. As Tmisone has already 

 been shown to be identical with the imoohi-ii/o of 

 Japan and the omo-mentek of Java, the evidence 

 is strong that blast is a world-wide disease which 

 has only recently reached America. In Italy the 

 disease is practically under control by use of re- 

 sistant varieties of rice. These were imported by 

 the author and will be tested in 1909. 



A Few Diseases of Bamboo and Sedge: Flora W. 

 Patteeson and Veea K. Chables, U. S. Depart- 

 ment of Agriculture, Washington, D. C. 

 This paper discusses a few diseases occurring 

 upon these hosts, their morphology, systematic 

 position and especially their economic significance 

 in relation to future foreign introductions. It 

 includes pathological and histological notes on 

 species previously known to cause diseases and 

 the description of a new genus. 



Specimens of diseased bamboo, and specimens of 

 diseased sedge with water-color illustrations of 

 the latter, accompanied the presentation of the 

 paper. 



Pathological Notes Concerning a Few Ornamental 



Plants: Flora W. Patterson and Vera K. 



Charles, U. S. Department of Agriculture, 



Washington, D. C. 



This paper discusses the occurrence of a Bo- 

 trytis disease of peony and chrysanthemum, in- 

 cluding cultural notes and statements as to pre- 

 ventive treatment. 



A new disease on Cyclamen caused by Colleto- 

 trichum is described together with cultural notes 

 on its development. 



Necrosis of the Grape: Donald Reddick, New 

 York State College of Agriculture, Cornell Uni- 

 versity, Ithaca, N. Y. 

 Necrosis is a very common fungous disease of 



the cultivated Labrusca varieties of grape in New 



York state, and it occurs also on the white scup- 



pernong grape in Alabama. 



The disease may be recognized as follows: 



Vines trimmed and tied up which fail to put out 

 shoots; a dwarfing of shoots and leaves and a 

 light setting of fruit; leaves reduced in size, 

 crimped about the margin and chlorotie; the 

 sudden wilting of vines in late summer; the pres- 

 ence of longitudinally ribbed excrescences, or 

 tuberculous masses on any part of the stem; 

 small, black, slightly sunken lesions on the green 

 shoots. 



This disease is caused by Fusacoooum viticolum 

 n. sp. The fungus causes a dry rot in the stem, 

 the effects on other parts, except lesions on the 

 shoots, being purely physiological. 



The fungus has been isolated from the interior 

 of many diseased stems, from lesions on green 

 shoots and from spores developed in stromata on 

 the surface of dead parts. Pathogenicity is not 

 yet absolutely demonstrated, but this is the only 

 organism constantly associated with such condi- 

 tions. The most serious effects of the fungus are 

 found in very young vineyards and it is thought 

 that this is due to the use of diseased cuttings for 

 stock. 



Root crowns are often frees from disease and 

 this affords a means of control, viz., by renewal 

 with a sprout from the root. 



A Blight of Cultivated (Hnseng caused by Alter- 

 naria Panax n. sp. : H. H. Whetzel, New York 

 State College of Agriculture, Cornell University, 

 Ithaca, N. Y. 



The greater part of the million dollars' worth 

 of ginseng now annually exported from the United 

 States is grown under cultivation. Though but 

 very recently brought under domestication, it is 

 known to be subject to a number of diseases. 



The most common and destructive disease is the 

 so-called Alternaria blight. It is characterized by 

 the appearance of brown cankers on the stems and 

 large watery spots in the leaves which may eventu- 

 ally involve the entire leaf and top. Badly 

 blighted plants appear as if drenched with boiling 

 water. 



The pathogenicity of the Alternaria constantly 

 occurring in the lesions has been definitely deter- 

 mined by inoculation. 



Experiments extending over three years have 

 shown that it may be controlled by the thorough 

 application of Bordeaux mixture. 

 On a Method of Developing Claviceps purpurea 

 Tul. with Notes on Claviceps rubra n. sp.: 

 H. H. Whetzel and Donald Reddick, New 

 York State College of Agriculture, Cornell Uni- 

 versity, Ithaca, N. Y. 

 Early in August, 1907, sclerotia of Claviceps 



