1917] DISEASES OF PLANTS. 353 



From a comparison of the average percentages of the inorganic elements in 

 healthy leaves and leaves in medium stages of mottling, data were obtained 

 which are considered not to show that the initial mottling could be accounted 

 for by deficiency in the transfer of the iron, calcium, magnesium, and phos- 

 phoric acid from the conducting system of the leaf stem and midrib to the 

 raesophyll tissue. On the other hand sharply localized yellow areas in old 

 orange leaves contained less of these elements than the adjoining green areas, 

 but whether this relation obtained in the initial stages of mottling was not 

 determined. In very badly mottled leaves there was found in general an in- 

 crease in the percentage of these elements in the conducting tissues, including 

 the leaf stems, indicating difficulty in their transfer to the mesophyll tissues, 

 probably because the leaf had become functionless. 



Relation of nitrogen to mottle-leaf, I. G. McBeth (U. S. Dept. Agr., Jour. 

 Agr. Research, 9 (1017), No. 7, pp. 248-250) .—In investigations carried on by 

 the author in cooperation with the California Citrus substation. Riverside, and 

 noted on page 352, in which a study was made of factors Influencing nitrification 

 and the forces controlling the distribution of nitric nitrogen as related to the 

 nutrition of citrus trees, much attention was given to the production and dis- 

 tribution of ammonia and nitrate and their possible relation to mottling, a 

 serious trouble of oranges and other citrus trees. Mottled orange leaves were 

 found to have a higher moisture content and in general a higher nitrogen con- 

 tent than healthy leaves of the same age from the same tree. Extreme mottling 

 is frequently found associated with high nitrate content, but the correlation is 

 said to be by no means an invariable one. 



A new species of Endotliia, S. C. Beuneb (Mycologia, 8 {1916), No. 5, pp. 

 2S9-242, pi. 1). — An account is given of a study by the author of a fungus said 

 to be common as a saprophyte or parasite on several species of Eucalyptus, 

 and saprophytic on mango (Manf/ifera indica), in the vicinity of Santiago, 

 Cuba. The fungus is an Endothia, somewhat resembling E. radicalis, but as 

 a result of studies by the author it is considered as a new species and has 

 received the name E. Iiavanensis. The pycnidial stage ha.s been observed on 

 Persea gratissima and Spondias mombin. The fungus is thought to be of 

 Cuban origin. 



Rose diseases, L. M. Massey (Anier. Florist, Ifl (1916), No. 1489, pp. 1148, 

 1149). — An extensive investigation of rose diseases was undertaken in 1916 by 

 the department of plant pathology of Cornell University in connection with the 

 American Rose Society. The preliminary .survey shows that on both indoor and 

 outdoor plants, powderj' mildew and black spot are more common than other 

 diseases, and the results of studies on these troubles are to be published later. 

 Two varieties are affected with a root or crown rot, which is described. Other 

 rose diseases are crown gall, Phyllosticta leaf spot, besides other leaf spots, 

 and cane diseases of unknown causation. 



A disease of Clivia under glass, G. Arnaud {Bui. Sac. Path. Veg. France 

 1 {1914), No. 1, pp. 36, 37, fig. 1). — A disease of Clivia in the gi-eenhouse is 

 described as due to the fungus Colletotrichum cliviw. 



An Alternaria on Sonchus, J. A. Elliott {Bot. Gaz., 62 {1916), No. 5, pp. 

 414-4I6, fig. 1). — A fungus said to cause a spot on leaves of S. asper, near 

 Madison, Wis., and also on Lactuca canadensis, is reported as having been sent 

 in by J. J. Davis, who has described the fungus as a new species under the 

 name A. sonchi. 



[Cucurbitaria pithyophila on Scotch pine in Scotland], C. M'Intosh {Trans. 



Roy. Scot. Arbor. Hoc, 29 {1915), pt. 2, pp. 209, 210; abs. in Internal. Inst. Agr. 



[Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 6 {1915), No. 11, pp. 1539, 



1S49). — A fungus parasitic on stems and branches of Scotch pine, noted near 



5750'— 17— No. 4 5 



