DISEASES OF PLANTS. 779 



kind of top rot characterized by the presence of much slime in cavities near the top 

 of the stalk. Different varieties of cane vary in their susceptibility to disease, some 

 being practically immune. It is said to be of easy control through the selection of 

 sound cuttings and the use of resistanl varieties. Attention is called to the Liability 

 of its transfer from one country to anoth.-r through the medium of slightly diseased 

 cuttings. 



The red string of the sugar cane, R. <i. Smith | Proc. Linn. Soc. X. S. Wales, 29 

 {1904)1 pt. 8, pp. 449-459, phi .>').— The presence of red-colored fibrovascular bundles 

 in sugar cane is said to be not at all uncommon, the phenomenon appearing to accom- 

 pany several diseases of the cane, as well as in some instances occurring in canes thai 

 are apparently healthy. 



Tlie author gives a description of a form investigated, to which the name red string 

 is given. This was observed in canes otherwise health} . as well as in plant- affected 

 with gummosis. Portions showing the red coloration were cu1 oul of cane and 

 transferred to culture media, from which the author obtained a mold and several 

 species of bacteria. The mold was found under certain conditions to produce the 

 reddish color, but did not produce any slime, while the bacteria produced the char- 

 acteristic slime. Of the 3 species of bacteria isolated only one was found capable of 

 producing the crimson red gum in the vessels of the cane. This organism was 

 studied and is described under the name Bacillus pscudarahiinis, n. sp. 



The red mold was also studied and is described at some length. The author was 

 unable to associate it with any hitherto described species, but from his characteriza- 

 tion he thinks it will be possible for other investigators to recognize it. 



The crown-gall and hairy-root diseases of the apple tree, <i. <.. Bedgcock 

 ( U. S. Dept. Agr., Bar. Plant Indus. Bui. 90, pt. 2, pp. 7, ph. S).—A preliminary report 

 is given of investigations on the crown-gall and hairy-root diseases of the apple tree, 

 for the purpose of calling the attention of apple growers to the different diseases and 

 to interest them in the collection of data regarding the predisposition of varieties to 

 these diseases. 



The author's investigations have resulted in separating what was previously called 

 the apple crown gall into two diseases. The disease now designated as crown gall is 

 a callous-like gall growth following wounds on some portion of the root system of the 

 tree and which rarely occurs above the ground on parts of the trunk or limbs. 



The malady now called hairy-root disease is evidently the same as the one first 

 named in New York State Station Bulletin 191 (E. S. R., 13, p. 148) and is charac- 

 terized both in seedlings and in grafted or budded trees 1>\ a stunted root system, 

 accompanied with an excessive production of small fibrous roots, often originating in 

 clusters from the main or tap root. Galls often occur in connection with the hairy 

 root, but these are the results of wounds rather than a form of the disease. 



The apple crown gall is of two types. In one a hard callus is formed on grafted 

 trees at the union of the root and scion, or at any other point of the root system 

 where wounds occur, and the results of extensive inoculation with this type have 

 failed to prove that this disease is of a contagious nature. The second type is a soft 

 form more common on seedlings, occurring rarely on grafted trees. These softer 

 galls resemble those of the raspberry and peach, in that they are soft and often rot 

 off, but it is not certain that they are replaced the following year by a new gro* th. 

 nor is there any proof that they are of a contagious nature. 



Nurserymen are advised to give careful attention to the selection of seedlings for 

 grafting and budding, rejecting all that show tufted or hairy roots, as these will 

 develop into hairy-rooted trees with a very deficient root system. So far as tin- 

 investigations go, this disease is not contagious. It is hoped that in the near future 

 practical means for reducing the percentage of trees affected with these diseases will 

 be known. 



23786— No. 8—0(3 5 



