652 EXPERIMENT STATION RECORD. 



oblong in outline. The two forms retain tlieir distinctive characteristics when 

 grown on the same culture medium. Both have been obtained from the fruit. 

 The pycnidia from cankers have nearly always contained the long spores. In 

 inoculations on foliage, positive results have been obtained only with the long- 

 spored form. The large number of leaf spots beneath cankers are believed to 

 furnish evidence of the transfer of the fungus from the limb to the leaves. 



Apple fruit spot and quince blotch, C. Bbooks and Caroline A. Black 

 (Phijtopnfhologij, 2 (1912), No. 2, pp. 63-72, pis. 2).— This paper includes a 

 ♦ second report on the fruit spot of apples (E. S. R., 20, p. 847) and a discussion 

 of a similar disease of quinces. 



A Phoma stage has been found for the fungus causing the fruit spot of 

 apples, and as a consequence the name of the fungus has been changal from 

 CyUndrosporium pomi to Phoma pomi. A spot similar to that on apples is 

 reported on quinces, and cross inoculations have shown that it is due to the 

 fungus mentioned above. This disease has been previously noted (E, S. R., 

 4, p. 656). 



Three destructive diseases of the peach, E. O. Essig (Mo. Bui. Com. Ilort. 

 Cah, 1 (1912), No. 8, pp. 337-359, figs. //). — These diseases are peach yellows, 

 peach rosette, and little peach. In case of each an account is given of the 

 history of the disease, its destructiveness, distribution, the plants attacked, 

 nature and symptoms of the disease, its modes of distribution, and recommen- 

 dations looking to its control. To this is added the author's correspondence 

 with various sources of information, also the California state quarantine law 

 relating to peach yellows and rosette. 



The method of spreading' of the olive knot disease, W. T. Horne, W. B. 

 Parker, and L. L. Daines (.\h><. in Phytopatholoffij, 2 (1912), No. 2, p. 96.).— 

 This is a progress report on studies carried out near Sacramento, Cal., to dis- 

 cover a method for controlling the olive knot disease due to Bacterium 

 savastanoi. 



No biting or piercing insect or other transporting agent was discovered, but 

 it was found that vigorous knots exude bacterial slime when wet. It was 

 demonstx'ated, both by platings from the slime and from direct inoculations, 

 that this sliiue contains the organism in abundance, and its dissemination is 

 accounted for by the spattering of rain, and the accidental transfer by birds, 

 insects, or other agencies. Entrance into the living bark is believed usually to 

 take place on healed wounds. 



Comparative experiments with certain sprays for controlling Peronospora 

 viticola on the grape, A. Bretschneider (Ztschr. Landw. Vcrsiidhnv. Osterr., 

 15 (1912), No. 2, pp. 1Jf7-152). — This series of experiments repeats with certain 

 extensions previous ones already noted elsewhere (E. S. R., 25, p. 751), results 

 being given in detail with discussions of comparative cost in employment of the 

 vai-ious preparations tested. 



The downy mildew fungi and their control, A. Bretschneider (Monatsh. 

 Landic, 5 (1912), No. 5, pp. 138-1 '17, figs. 6). — Continuing the above the author 

 gives a brief discussion of certain Peronospora ceae as enemies of various fruits, 

 trees, wild plants, etc.. with recommendations as to preventive and remedial 

 measures. 



A knot of citrus trees caused by Sphaeropsis tumefaciens, Florence 

 IIi'jJGES and L. S. Tenny (U. 8. Dept. Agr.. Bur. Plant Indus. Bui. 2.'i7, pp ?'-{, pis. 

 10, figs. 8). — This bulletin gives an account of an infectious disease of citrus 

 trees which has caused extensive losses in Jamaica. The same or a similar 

 trouble has been recently discovered in the T'nitcil States. The investigations 

 reported have extended through a period of G years, during which time the 



