DISEASES OF PLANTS. 653 



finally disintegrated. The nucleus moved from a peripheral position toward 

 the center of the cell. There was also a distinct increase in the size of the 

 nuc>eus while the chromatin gradually diminished in quantity. 



Contributions to a knowledg-e of " the snap-beech " disease, Elsie M. Prior 

 (Jour. Econ. Biol., S {1918 ), Nu. Jf, pp. 2Jf9-263, phs. 2).— The author gives an 

 account of studies made on a fungus disease of beech causing trees to break at 

 a point usually 15 to 20 ft above ground, the rest of the trunk remaining sound. 

 The disease is attributed to PoJyporus advsius, which is said to be a wound 

 parasite. An account of its activity in this connection is given. Several enzyms 

 named were prasent in the mycelium. 



Chestnut blig'ht and its control in West Virginia, A. B. Brooks (IF. Va. 

 Crop Pest Coin. Bui. 2 (1913), pp. 12-16, figs. 2).— This Is a brief account of the 

 history, distribution, and attempted control of chestnut blight in West Virginia. 

 Radical sanitary surgery in case of trees valuable for shade, ornamentation, etc., 

 and complete eradication of forest trees affected are measures insisted upon. 



The relative prevalence of pycnospores and ascospores of the chestnut 

 blight fungus during the winter, F. D. Heald and M. W. Gardner (Phyto- 

 pathology, 3 (1913), No. 6, pp. 296-305, pis. 5).— A detailed account is given of 

 a study of the dissemination of the pycnospores and ascospores of the chestnut 

 blight fungus, a preliminary account of which has already been noted (E. S. R.. 

 29, p. 351). It was found that viable pycnospores of the chestnut blight fungus 

 are washed down the trees in large numbers during every winter rain, ])ut no 

 ascospores were washed down by the rains during the period covered by the 

 test. 



Notes on oak mildew, E. Noffray (Bui. Soc. Nat. Agr. France, 75 (1913), 

 No. 6, pp. Jf7.HP"7).—lt is stated that in 1912 the attack of oaks by Oidium 

 quercinum appears to have been less severe than in recent years. The Ameri- 

 can oak (Quercxis palustris) continues to show greater resistance to attaclv by 

 this fungus than do the native species. 



[Desti'uction of coniferous seedlings by Fusarium], G. Iajstner (Bei'. K. 



Lehranst. Wien, Obst u. Gartenbau Geisenheim, 1912, pp. lJt8-150, fig. 1). 



A disease of conifer seedlings, causing in a short time a loss of 70 per cent of 

 the plants, is briefly reported upon. The trouble is thought to be due to a 

 Fusarium. 



Production of secondary sporidia by Gynmosporang-ium, C. H. Crabill 

 (Phytopathology, 3 (1913), No. 6, pp. 2S2-2S4, fig. i).— The author reports ob- 

 serving secondary spores formed by the germinating sporidia of G. juniperi- 

 virginia7iw while conducting some investigations on the cedar rust in 1913. 

 Secondary sporidia have also been obsen-ed by him in G. clavipes, and it Is 

 thought that probably this phenomenon may occur in other species of Gymno- 

 sporangium. 



Notes on Cronartium comptoniae, II, P. Spaulding (Phytopathology, S 

 (1913), No. 6, pp. 308-310). — In a previous publication the author gave some 

 data concerning the eastern pitch pine blister rust caused by the fungus C. comp- 

 toniw. This fungus was not thought to be of economic importance, as it seemed 

 at that time to be confined to a number of species of Pinus which have little 

 value as timber trees. Later It was observed on P. pondcrosa, and it is prob- 

 able that it would prove a serious enemy of that species of pine should it ever 

 be grown in any quantity in the East. P. sylvestris is also said to be a host 

 of this fungus. 



The introduction of a European pine rust into Wisconsin, J. J. Davis 

 (Phytopathology, S (1913), No. 6, pp. 306, 307).— The author reports the occur- 



