DISEASES OF PLANTS. 747 



blotch (Actinonema rosw), blight of ginseng (Altemaria panax), and sooty 

 blotch of apples (Leptothyriutn ponii). 



Phytopathologic notes, G. Arnaud (Ann. Ecole Nat. Agr. Montpellier, n. 

 ser., 12 (1912), No. 1, pp. 5-22, figs. '.)). — The author gives the results of studies 

 on several parasitic fungi substantially as follows: 



f^phcvropsis pseudo-diplodia, a very vari.'ible fungus occurring on mnny woody 

 plants, is considered to include properly several forms known by other names 

 as species of Sphteropsis, Macrophoma, Diplodia, etc. Physalospora cydonice 

 is thought to be the perfect form of 8. pHCudo-dlplodia. The latter is a weak 

 parasite, attacking usually plants or parts already injured or weakened from 

 other causes, increasing the injury, and hastening death, or else only forming 

 cankers in ease of resistant plants. The fungus is often found in relation 

 with the work of a bark-boring beetle (Scolytus). 



Phoma (Fusicoccum) cincrcscens, the pycnidial stage of Diaporthe cineres- 

 cens, is said to be the only vegetal parasite seriously affecting Ficufi carica, 

 causing on twigs, branches, and trunk extensive cankers which slowly destroy 

 the tree, the annual loss therefrom being important. The progress of this para- 

 site is found to be closely related to the inroads of a minute beetle, Hippoborus 

 ficus. 



Gloposporium nervisequnm, said to be the pycnidial form of Onomonin reneta, 

 causing anthracnose of the plane tree, produces in spring alterations along the 

 Aeius of the leaf and in autumn along the borders, causing yellowing of the 

 leaves and drying of the branches affectetl. 



Plant pathology, F.. .1. Butler (Ann. Rpt. Bd. Sri. Advice India, 1910-11. 

 PI). 112-111). — Notes are given on several diseases of the palm, soft rot of 

 ginger (ascribed to Pythium gracile), a leaf disease of turmeric (said to be 

 due to a species of Taphrina), a parasitic disease of the tea bush and one of 

 tea seed, some forest tree diseases, fruit diseases, etc. A brief bibliography 

 is appended. 



Contributions to the study of straw blight of cereals, G. Feon (Ann. Sci. 

 Agron., 4. so:, 1 (1912), I, Xo. 1, pp. 3-29, figs. 3; abs. in Internat. Inst. Agr. 

 [Rome], Bill. Bur. Agr. Intel, and Plant Diseases, 3 (1912), No. 4, pp. 1054- 

 1056). — Black foot or straw blight, which has been attributed to OphioboUis 

 graminis and Leptosphceria herpotrichoides, is held by the author, as the result 

 of his studies, to be due to the latter organism. This fungus appears in May 

 or early in June, spreading rapidly and showing as a felt-like mass on the 

 stalks, which turn gray and finally wither. The mycelium penetrates the cells, 

 preferring those near the vascular bundles. The black perithecia appear inside 

 the leaf sheaths about September, and in November and December contain a 

 large number of spores which escape in cold, dry weather and easily infect the 

 young wheat plants. Infection of older plants is rare and difficult. The 

 mycelium lives through the winter and in the next fall produces a still larger 

 number of perithecia. 



The incubation period is long. The spores retain their power to germinate 

 while in the perithecia. but on escaping soon germinate or perish as they lose 

 their vitality quickly in light (especially sunlight) and in dry air. these con- 

 ditions also retarding mycelial growth. The spores were found much more 

 resistant to iron sulphate than to the corresponding copper salt. 



The author thinks that the conidia attributed to a supposedly new fungus 

 found in May, 1909. and provisionally named CercosporelJa herpotrichoides, are 

 the summer fructifications of L. herpotrichoides. The fungus requires an 

 alkaline or a neutral medium for its development, growth being checked by very 

 slight acidity. 



