194 On Diseases of Plum Trees 



Summary. 



(1) A disease or diseases of plum trees believed to be caused by 

 one or more species of Cytospora has been described. 



(2) The fungus isolated in most cases is closely related to or identical 

 with Cytospora leucostoma. 



(3) Complete germination of the spores took place only in presence 

 of organic nitrogen. 



(4) Pycnidia and spores were obtained in artificial culture, similar 

 to those occurring in nature. 



(5) Attempts to induce perithecial formation failed. 



LITERATURE. 



1. Aderhold, B. "Ueber das Kirschbaumsterben am Rheiii." Arb. aus der 



Biol. Abth. fiir Land. u. Forst, wirthschaften am Kais. Gesundheitsamte, Baud 

 in, Heft 4, 1903. 



2. Harper, L. L. and Field, E. C. "A dry rot of potatoes caused by Diaporthe 



batatis." U.S. Dept. of Agric. Bureau of Plant Industry, Bull. 281. 



3. Shear, C. L. and Wood, A. K. "Studies of Fungus Parasites belonging to the 



genus Glomerella." U.S. Dept. of Agric. Bureau of Plant Industry, Bull. 252. 



4. Massee, G. "A disease of nursery stock." Gard. Chron., Sept. 27th, 1902. 



5. Wormald, H. "A Cytospora disease of the cherry." S.E. Agric. Coll. Journ., 



No. 21, 1912. 



EXPLANATION OF FIGURES. 



Pig. 1. A piece of diseased hark of Victoria (.'5). Nat. size. 



Kg 2. T.S. of pycnidia of Victoria (3). x 80. 



Fig. 3. A piece of diseased bark of Victoria (4). Nat. size. 



Fig. 4. A piece of diseased bark of Prince of Wales (5). Nat. size. 



Fig. 5. L.S. of diseased wood of Prince of Wales. x 300. 



Fig. 6. L.S. of wood of diseased Prince of Wales branch., above hyphae. x 220. 



Fig. 7. T.S. of diseased wood of Prince of Wales. x 800. 



Fig. 8. Germinating spores of fungus from Victoria (1). x300. 



Fig. 9. Petri disli culture of fungus from Victoria (1) on raisin agar. 



Fig. 10. Petri dish culture of fungus from Pond's Seedling (7) on raisin agar. 



