DISEASES OF PLANTS. 453 



attacks of the finigi by the use of Bordeaux mixture or other fungicides. The 

 author calls attention to the copper soda spray as a substitute for Bordeaux 

 mixture, but where fresh liiue is available, he thinks that the Bordeaux mixture 

 as commonly made with lime is to be preferred. 



Notes are also given on bitter pit disease of apples, which seems to be due to 

 physical conditions in tlie environment of the tree which are unfavorable to a 

 perfect development of the fruit, and on Entomosporium spot disease. 



Notes on some diseases of apple trees, E. Prillieux (Bui. Soc. Nat. Agr. 

 France, 68 (1908), No. J. pp. 286-291). — ^An examination was made of twigs 

 from apple trees which were submitted to the station of plant pathology, from 

 which it was found that they were in most cases attacked by Xccfria (lifissima, 

 causing cankers. 



The effect of the fungus on the twigs is descril)ed, and the author states that 

 the disease is not a new one, as was feared by the owners of the oi'chard, but 

 was mostly caused by the presence of the Nectria mentioned above. In addition 

 he found some other fungi present, particularly ^lonilia. 



For jireventing the injury, the author recommends the use of resistant varie- 

 ties, better drainage of the soil, the burning of diseased twigs, and winter treat- 

 ment with fungicides. 



A new form of Sphseropsis on apples. Leva B. Walker (Xehra.ska Sta. Rpt. 

 1901, pp. 34-H, M^- ^0)- — Two forms of Sphreropsis have been observetl which 

 are capable of producing a severe black rot of the apple. In macroscopic ap- 

 pearance the rots are verj' much alike, the principal differences in the 2 forms 

 being the size of the spore, the size and thickness of the pycnidium, and the 

 absence of the ostiole in the new form. The new form has decidedly longer 

 spores than is commonly described for »S. mnlorum, and it seems to be a much 

 more vigorous grower and to do more damage than the common form. Whether 

 the long-spored form should be considered a new species or a form of S. malo- 

 rum, is not determined. A bibliography is given. 



Studies on the genus Gymnosporang'ium, F. D. Keen (Bnl. Torrey Bot. Club, 

 3.1 (1908), No. 10, pp. Jf99-511). — A study has been made of the so-called cedar 

 apples and rusts associated with them for the purpose of bringing together data 

 in such a manner as to be of material assistance in the determination of the 

 North American species. A key is presented involving the more evident diagnos- 

 tic characters and indicating the host plants for each. Preceding the key, notes 

 are given on some of the species, exi)lanatory of their nomenclature, extension 

 in range, and other interesting features which have been revealed in the investi- 

 gations. 



A disease of cloves, H. N. Kidley (Agr. Bui. Straits and Fed. Malay States, 

 7 (1908), No. 7, pp. 263, 26'/). — The cultivation of clove trees is said to have been 

 an extefisive industry at one time in Singapore, but it has almost ceased to be of 

 importance owing to disease. An old tree in the Singapore Botanic Gardens 

 gave the author an opportunity for studying the cause of the trouble, and he 

 found the tree aiTected by a red-spot fungus. 



The fungus forms dark red spots on both surfaces of the leaves, the spots 

 increasing in size until they attain a diameter of 0.2 in. or more. The leaf is 

 often attacked when just opened, before it has attained its full green coloring, 

 and the author is inclined to think that the attack most commonly begins in the 

 bud. The fungus has not been definitely determined, but it appears to belong 

 to the Peronosporacese. 



The author believes that the fungus destroys many seedlings through attacking 

 the buds, and that spraying with a weak solution of Bordeaux mixture would 

 protect them from attack. 



