62 EXPERIMENT STATION EECOED. [Vol.88 



infection at the cutting bench and to an early breaking down of some sort in 

 the tissue, which later develops into yellows. Overpropagation may also favor 

 yellows by lowering the vitality of the cuttings. Of cuttings, layers, and shoots 

 taken from apparently healthy seedlings and grafted on stock which was badly 

 diseased, the first two showed little if any indication of yellows, while the 

 grafted stock yellowed badly, leaving but little doubt that the disease can be 

 communicated to healthy plants by grafting. 



Some factors influencing the prevalence of Endothia gyrosa, N. B. Stevens 

 (Bui. Torrey Bot. Club, U {1911), No. 3, pp. 127-m, figs. 5). — In pursuance of 

 the work previously noted \\ith E. parasitica (E. S. R., 37, p. 557), the author 

 states that the distribution of the American species of Endothia does not coin- 

 cide with that of their hosts. The present paper deals with E. gyrosa, said 

 to have a much wider range in America than any other species of this genus 

 and to be indigenous here with a long history as Indicated. It is, however, 

 abundant only in the Southeastern States. 



Inoculation experiments during 1914 and 1915 have shown that this fungus 

 can grow and overwinter beyond the northeastern limits of its present known 

 range, and have emphasized the importance of water supply and of the condi- 

 tion of the host in relation to the growth of the fungus. It thrives best on 

 injured tissue which remains moist for a time, as cut limbs or injured roots. 

 The temperature of the Southern States is more favorable to the fungus than 

 is that of the Northern States, the division line between regions of its rarity 

 or its abundance being fairly definite, this fact suggesting some significant 

 factors other than climate. The chief of these appears to be Increased oppor- 

 tunity for infection in the Southern States, due to the increase there in num- 

 ber and relative importance of its host plants and to the increased opportunity 

 for infection due to soil and cultural conditions causing greater erosion and 

 consequently more frequent exposure of the roots of Fagus and Quercus to 

 injury and infection. 



[Chestnut bark disease], H. Metcauf {North. Nut Growers Assoc. Proc, 7 

 (1916), pp. 41-54). — It is stated that during the first year or more of its life 

 the chestnut (even in the case of sprouts growing from diseased stock) is 

 immune to attack by the chestnut bark fungus. No evidence has been obtained, 

 however, that the disease is stopping naturally anywhere in its progress, 

 which is now very widespread. Cutting out affected parts of trees which have 

 been attacked is effective but too expensive to be profitable. No immune native 

 trees have been found, but some Asiatic chestnuts appear to be more or less 

 resistant. 



[Diseases of the English walnut], S. M. McMubban (North. Nut Orowers 

 Assoc. Proc, 7 (1916), pp. 67-79). — In this discussion, which also referred to 

 the so-called winterkilling and to other more or less obscure troubles of walnut 

 trees, it was stated that walnut blight has been found at a number of points 

 in New Jersey, Delaware, and Pennsylvania, leading to the view that the 

 disease has been present in this section for a long time. It is apparently less 

 actively pathogenic here than in California (where spraying has not proved 

 economical), but it is thought that selective breeding for resistant forms will 

 prove to be the most effective measure looking to its control. 



Observations on some diseases of plantation rubber in Malaya, F. T. 

 Beooks (Ann. Appl. Biol., 2 (1916), No. 4, pp. 209-227, pis. 3). — This is an ac- 

 count of observations on diseases of plantation rubber during 1914, some of 

 which have already been published (E. S. R., 34, pp. 57, 448). The several 

 sections of this article deal with Fames Ugnosus, Polyporus rugulosus, Sphwros- 

 tube repens, Hymenochmte noxia, UstiUina. zonata, Botryodiplodia theobromce, 

 bark diseases, bars, thread blight associated with CypheUa hevete and perhaps 



