552 EXPEKIMENT STATION EECORD. 



The mildew of oaks, E. Griffon and A. Mai^blanc (BuL Trimest. 8oc. 

 Mycol. France, 26 {1910), No. 1, pp. 132-137, fig. 1).—A study has been made of 

 the mildew of the oak, in which the authors have sought to determine the rela- 

 tionship of the fungus to other species. As a result of their investigations they 

 have decided that the disease is due to a conidial phase of an unidentified 

 species, and they have given to it the name O'idium alphitoides n. sp. 



A fung-us disease of the lebbek tree, W. L. Balls {Cairo Sci. Jour., 4 

 {1910), No. Jfl, p. -^2). — The author states that the avenues of lebbek trees in 

 Cairo are suffering through scale insects aiid other troubles, and that an exami- 

 nation of trees blown down in the spring of 1908 showed that the roots were in 

 many cases damaged by rot, leaving only 1 or 2 sound ones. The rot appeared 

 to have begun at the basal stump and spread into the roots, and the trees exam- 

 ined seemed to have been planted as cuttings, the cut end being left open to 

 attacks of disease-producing organisms. The fungus was unrecognized by the 

 author, but is believed to have been the primary cause of the trouble. 



AVhile no remedy is known when the trees are once attacked, it is advised 

 that when planting these trees the cut ends be covered with tar and grafting wax 

 before placing them in the ground. 



Notes on the disease of Pterocarpus in Penang, W. Fox {Agr. Bui. Straits 

 and Fed. MaUnj States, 9 {1910), No. .'/, pp. 136, 13)). — A brief account is given 

 of the occurrence and spread of a disease of P. indicus in the Malay Peninsula 

 due to Polystictus occidentaUs, which has already been noted (E. S. R., 2.3, p. 

 354). 



On the genetic relation between Coleosporiuni on Aster scaber and Peri- 

 dermium pini-densiflorse, Y. Okishimo (Bot. Mag. [Tokyo], 2Jf {1910), No. 276, 

 pp. 1-5). — As a result of inoculation experiments the author is led to believe 

 that the two forms of fungi, P. pini-densiflonp occurring on Pinus densiflora and 

 C sonclii on .4. seaber, have been proved to be genetically related, and that the 

 fungus should in the future be known as C. pini-asteris. 



Leaf disease in Hevea, Mevr. A. E. van Hall-de Jonge {Dept. Landb. 

 Surinanie Bill. 2.'i, pp. 6. pis. 2). — In 1908 Hevea plants in the nursery of the 

 botanic gardens of Surinam were observed to be attacked by a leaf disease. 

 The leaves showed spots which spread over them in concentric circles. Only 

 the young leaves appeared to be attacked. The cause of the disease is a fungus 

 living on the under side of the leaves, the identity of which is not definitely 

 known. While the disease appears very infectious and spreads rapidly, it is 

 believed to be due to accidental circumstances, especially to too close planting. 



Die back of Hevea brasiliensis, T. Petch (Circs, and Agr. Jour. Roy. Bot. 

 Gnid. Ceylon. J, {1910), No. 23, pp. 307-321).— It is stated that die back is caused 

 by two different fungi. One, Glwosporium alborubrum, a true parasite, origi- 

 nates the disease by attacking the leading green shoot in the middle of its 

 length, producing dark brown discolorations which extend upward and down- 

 ward until the entire shoot becomes diseased and finally dies. The other, 

 Botryodiplodia elastiea^, a wound parasite, enters the tree through the dead top 

 shoot after it has been killed by the Gloeosporium fungus and causes the chief 

 damage in die back by growing downward in the woody stem and gradually 

 killing it to the ground. 



The promi)t cutting out of the diseased shoots and a thorough tarring of the 

 wounds are usually efficient remedies for this disease. 



The fungus {B. elastieop) is known to occur in other countries on cacao (stems, 

 roots, and pods), sugar cane, Albizzia moluccana (roots), papaw (stems), 

 mango (fruits), and Castilloa (stems), while in Ceylon it grows (1) on H. 

 brasiliensis, killing back the main stem, causing the death of stumps, or living 



