IN describing a number of new plant diseases in i883 FRANK' gave an account of peculiar spore-like organs produced by the germ tubes of spores of the bean anthracnose. He showed further that these organs acted as holdfasts, by means of which the fungus was firmly attached to its host during the early phase of development. In the same paper he described analogous organs of Fusicladium Tremulae and Polystigma rubrum. Almost simultaneously FiSCH2 described the holdfasts of Polystigma, but he did not at all recognize their true significance. He regarded them as ''secondary spores" which served in the distribution of the fungus, since the ascospores are embedded in slime when ejected, and are therefore not suited for dissemination by the wind. FRANK first recognized the true nature of these bodies, and gave to all organs of this class the name appressoria or adhesion organs. Later MEYER3 again described and figured the adhesion organs of Polystigma, but added no new observations. In i886 DE BARY4 first showed that the complex adhesion organs of Sclerotinia were produced as the result of a mechanical stimulus, but BtSGEN5 made the most complete study from a physiological standpoint. He showed that the germ tubes of many parasitic fungi produce adhesion organs of I FRANK, B., Ueber einige neue und weniger bekannte Pflanzenkrankheiten.

Many of the constituents of wheat plants have been repeatedly and thoroughly investigated. In Wehmer's book, "Die Pflanzenstoffe," second edition, 1929, mention is found of a considerable number of organic and inorganic constituents. However, the non-volatile organic acids are not mentioned.In the course of a study on the buffer system of the wheat plant,4 Hurd-Karrer found that the form of the titration curve between Pa 2.0 and 6.0 suggested the presence of malic acid in the juice, which observation directed attention to the fact that the nature of the organic acids of wheat had not been reported. The present work was accordingly undertaken, in cooperation with the office of Cereal Investigations of the United States Department of Agriculture, to determine the identity and relative amounts of the acids in the tissues of the wheat plant.The material used for this study was winter wheat grown on the Arlington Experimental Farm at Rosslyn, Virginia, during the season of 1927-1928. Samples were collected from May 15 until May 28, 1928. The plants at this time were in a vigorous state, free from rust and other diseases.

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The directive influence of gravity in determining the position of the hymenium in the higher Basidiomycetes is a matter of common observation. The fruit-bodies of these fungi are universally oriented so that the hymenium is exposed toward the earth's surface. If the normal position of the fruit-body is changed, either by accident or by experimentation, readjustment takes place by which the hymenial surface is again brought into a horizontal plane, provided of course that such readjustment is not hindered by other factors. Interesting cases illustrating these phenomena are given by ATKINSON' and also by WATERS.2 The methods by which the horizontal orientation of the pileus is brought about are two. First, in all stalked forms, such as the Agaricaceae, and some of the Polyporaceae and Hydnaceae, the stalks are negatively geotropic, and by their curvature always bring the pileus into a horizontal position. This property was first observed by HOFMEISTER3 in some of the Agaricaceae. The phenomena may be observed in all stalked forms growing on the sides of trees or stumps. Here the stems curve upward until the pileus is brought into the normal position. Second, in forms which have no stalk, and this applies especially to sessile forms of Polyporaceae, the orientation of the hymenium is brought about by the growth of the trama-plates themselves, for, as SACHS4 has shown, the trama-plates of the hymeno-

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