DISEASES OF PLANTS. 453 



to 1)0 infoetod with a s]»ocios of Lasiodiiilodia. but wliother the fuiis^ns is L. 

 tubcricola or a new sjtecies is yet to be detenuiiied. 



It is thouiilit ])ossibIe tiiat this fungus may l)e connected with liie witclu>s' 

 broom disease, whicli is so destructive to cacao, but as yet tiiis lias not been 

 established by cultural exiK'riments. 



A bacterial disease of oleander, ('. <^. Smith {Bot. Gaz., 42 (1906), No. 4, 

 III). Sl)l-,il(). fifiH. .'/). — An exanunation was made during the autumn of 1005 of 

 some diseased oleanders whicli were sent to the pathological laboratory of the 

 rniversity of California. 



These plants were affected with large. h:ird, woody knots on stems and leaves, 

 and their appearance suggested the possibility of tluMr relationshi]) with the 

 olive disease known as olive knot or tuberculosis. Cultural experiments were 

 carried on with the organisms ciiusing the disease and reciprocal artificial 

 inoculations were made from the olive to the oleander. It was foiuul that the 

 disease in both is caused by the same organism. The cultural characteristics 

 of the organisms isolated from both plants are essentially alike in all res])ects. 



The Alternaria blight of ginseng, H. FI. Whetzel (Cornell (Unnifri/HKin. 

 Jj (1!)()G). Xp. 2, pp. 33-41, ti!/f<. .9). — The cultivation of ginseng, having become 

 of considerable economic importance, has led to a study of a number of dis- 

 eases, and the author describes the Alternaria blight, which has proved ex- 

 ceedingly d(>structive in some localities. The species of Alternaria has not yet 

 been determined, but from experiments it has proved to be tndy parasitic and 

 constantly associated with the disease. 



A description is given of the effect of the fungus on the host plant, particu- 

 lar attention being paid to the destruction of the seed crop. For the preven- 

 tion of injury it is recommended that the iilants be sprayed with ;i 4-0-40 

 solution of Bordeaux mixture, to each 100 gal. of which is added about a g.al- 

 lon of a resin-soda mixture. 



Infectious chlorosis of some mallows, E. Bauk (Hifzber. K. Preiiss. Akad. 

 TF/s.y., 1906, Xo. 1; ahfi. in Bot. Ceiitbl. 103 (1906), No. 2, p. 21).— An account 

 is given of experiments with a form of chlorosis observed ui>on certain species 

 of Miilvacea'. 



The investigations show that it is infectious within certain groups, but no 

 organism of any kind could be found associated with it. The disease is at- 

 tributed to the proI)able action of some of the metabolic products of the weak- 

 ened plant. 



A new disease of Erythrina, .1. M. .Tanse (Ann. .Tnnh Bot. Biiitrnzorf/. 2. 

 SCI'., .) (1906). pt. 2. pp. 15.3-197, pis, 6). — For a number of years a destructive 

 disease of Erythrina, an important coffee shade tree, has been observed in 

 .Tava, and studies have been carried on to determine its cause. 



The disease has been found to be due to bacteria, the principal point of 

 attack being the roots, but very characteristic effects are produced in the 

 trunk, branches, and leaves. The bacteria seem to secrete two enzyms. one 

 of which attacks the lignified cells, while the other dissolves the cellulose. 



Studies upon some chromogenic fungi which discolor wood, G. G. Hedg- 

 cocK ( .]f(). Bot. Ganl. A)ni. Rpt., 17 (1906), pp. .7.9-/7'/, pis. 10. fir/s. 3: .lour. 

 Mijcol.. 12 (1906), No. S.l, pp. 2fl// -2/0). —This investigation was undertaken 

 primarily as a study of chromogcMiic fungi which are concerned in the coloi- 

 reactions which take place in stained timber and also on account of the losses 

 to the hnnbcr industry due to the lowering of the gi-adc of luinbci- in piles 

 through the .-irtion of many wood-staining fungi. .Mtcntiim has Iieeu given 

 not only to tliusc which deeply ]tenetrate wood :iiid st.iin it, iiut also to those 

 which discolor it superficially. 



