DISEASES OF PLANTS. 1143 



some forms of chrysanthomums, and is imicli more injurious than the hlaik 

 rust because of its attacUinu tlie liost plants wliile quite young and also on 

 account of its rapid iiropagatiou. The repeated use of Bordeaux mixture is 

 said to be very effective in preventing this rust. 



All of the rusts mentioned occur on the wild chrysanthemum (L'liryfinnthc- 

 mum decaisncanum) . They also have a tendency to occur on C. sinense, al- 

 though in some parts of Japan there seems to be more or less specialization 

 regarding their hosts. 



A bacterial gall of the daisy and its relation to gall formations on other 

 plants, C. <). TowNSKND (Ab.s. in iSviciice, n. scr., 29 {1909), No. 737, /j. 273). — 

 Investigations on the galls occurring on the Paris daisy have been carried on 

 for some time by the author. After repeated efforts an organism was isolated, 

 which has the ability to induce the formation of new galls upon healthy plants 

 when inoculated into the stems and branches or even into the leaves of healthy 

 daisy plants. 



This organism will also produce galls upon a large number of other plants, 

 including the tomato, potato, tobacco, sugar beet, hop, carnation, grape, rasp- 

 berry, peach, and ai).ple. The work has led to the isolation of pathogenic or- 

 ganisms from the galls of peach, the hard gall of api)le, hairy root of apple, hop, 

 rose, and chestnut. The organisms obtained from these galls are cross inoc- 

 ulable and are very similar if not identical in size, shape, structure, and habits 

 of growth with the organism from the daisy gall. 



These investigations, the author claims, leave no doubt regarding the cause of 

 the crown gall of the peach as well as of some of the gall formations upon the 

 apple and other economic plants. 



Leaf spot of Odontog'lossum, M. C. Potter (Gard. Chron., 3. .scr., .{.5 (1909), 

 No. 1158, i>i). l-'io, l'i6, ftys. //). — The attention of the author has been directed to 

 numerous black spots occurring on the lower surface of the leaves of O. uro- 

 ftkiintcri. The .spots are found chiefly on the older leaves, the younger ones 

 being almost, if not entirely, unaffected. 



Transverse sections through the region of the spots show an accumulation of 

 a brown mucilaginous or gummy substance beneath the epidermis. In the 

 initial stages this substance is present only in the respiratory cavities of the 

 stomata, from which it exudes into the stomatal oi)enings. In more advanced 

 stages it collects in large masses, spreading through the hyiuxlermal cells into 

 the internal tissues of the leave.s. 



This leaf spot disease is said to differ in many respects from the common leaf 

 spot of orchids, which is chai'acterized by the plasmolysis of the cells. 



No fungus. has been found associated with this leaf spot, but numerous bac- 

 teria are present in the affected tissues. Thus far all attempts to induce the 

 disease upon healthy plants by inoculation with bacteria have proved unsuc- 

 cessful, but the author believes that bacteria play an important part in the 

 develojinient of the disease, particularly in the formation of the gum. It is 

 thought that unsuital)le cultural conditions are also largely responsible for the 

 initial occurrence of the disease. 



The transmissibility of the cause of olive tuberculosis to the oleander, L. 

 SAVA.STANO (liol. Aihoi. Iliil.. ', ( I'.iDS). \i>. 2. iij'. W. 87).— As a result of inocu- 

 lation experiments with pure cultures of the organism causing olive tubercu- 

 losis and of the insertion of fragments of olive tubercles into healthy oleander 

 trees, the author states that the bacterial disease of the olive can not be trans- 

 mitted to tlH' oleander. ,is claimed by ( ". < ). Smith i K. S. IJ.. IS. p. A~>:^). 



Beport of the Phytopatholog'ical Institute of Wag'eningen for 1907, J. 

 ItnzKMA P.os (M(<l<il. liijLs Ui>ii</<ic Ldiid. 'I'liiii en liosilihoii irscli.. I'.KIS, Vo. /, 

 PI). 33-137). — A descriidion is given of the organization of the institute for the 



