ZOOLOGY AND BOTANY^ MICROSCOPY, ETC. 229 



and that the reason of the failure of the ordinary reactions is the 

 intimate mixture of the cellulose with a foreign substance. In order 

 to eliminate this, it is necessary to treat it for a prolonged period — in 

 some cases several weeks — with potash, and then to wash with a weak 

 acid, after which the blue colouring with chloriodide of zinc is 

 obtained. This treatment was successful with Agaricus campestris, 

 Polyporus Bibis (?j, and fomentarius, the sclerotia of ergot, and some 

 lichens ; with Mucor and Saccharomyces it has not hitherto been fully 

 successful ; with Doedalea quercina the application, in addition, of 

 Schultze's maceration was necessary. 



With regard to the nature of the substance which prevents the 

 cellulose-reaction, the author determined, in Bcedalea and other 

 instances, the presence of suberin, by the formation of insoluble 

 cereinic acid or treatment with nitric acid and potassium chloride. 

 In the mushroom he believes he has also determined the presence of 

 proteinaceous substances. 



** Mai nero " of the Vine.* — The vines in the South of Europe, 

 and especially in Sicily, and South Italy, have been attacked, since 

 1863, by a disease known as " mal nero," which has inflicted great 

 injury upon them ; but its exact nature has not heretofore been 

 determined. At the instance of the Italian Government, G. Cugini 

 has now undertaken its investigation, and with the following 

 results ; — 



The presence of the disease is indicated by the appearance, in the 

 spring, of black streaks and spots on the branches, leaf-stalks, and 

 veins, and on the tendrils and stalks of the branches, penetrating 

 internally to the duramen. It must not be confounded with the 

 anthracnose (vajolo) caused by Gloeosporium ampelopliagum (Sphaceloma 

 ampelinum). 



The disease is caused by a parasitic fungus, a variety of SpTice- 

 ropsis Peckiana Thiini. In the interior of the diseased stems and 

 branches was found abundance of a brown mycelium, which de- 

 veloped especially in the cambium, and between the epidermis and 

 cork-layer. In the parenchymatous tissue of the bark and wood was 

 also found a great quantity of a yellowish-brown granulation, the 

 exact nature of which was not determined. The particles appear 

 to be crystals of calcium tartrate, the result of a hindering effect 

 produced by the fungus on the assimilation of the food-materials 

 absorbed through the root. They are found chiefly in the roots, leaf- 

 stalks, and branches, where the mycelium is comparatively speaking 

 absent. 



Roesleria hypogsea parasitic on the Vine.t — G. Le Monnier has 

 found a disease of the vine closely resembling that caused by 

 phylloxera, to be produced by a parasitic fungus which he identifies 

 with Boesleria hypogcea v. Thiim. But since that genus was founded 

 on the special form of the spores (which Le Monnier does not 



* G. Cugini, ' Ricerche sul Mal nero della vite.' 25 pp. (3 pi.). Bologna, 1881. 

 See Bot, Centralbl., viii. (1881) p. 147. 



t Bull. Soc. Sci. Nancy, xiii. (1881) p. 69. See Bot. Centralbl., viii. (1881) 

 p. 47. 



