1917] DISEASES OF PLANTS. 553 



the field. Infected soil gave negative results. Seed which had been placed in 

 water at 60* 0. showed twice as high a degree of infection as did the control 

 seed, owing supposedly to the weakening effect of the hot water upon the seed. 



Flower-bud and boll shedding of cotton in the Iloiin Province, Nigeria, 

 T. Thornton {Trans. S. Internal. Cong. Trap. Agr. 1914, vol. 1, pp. S79-S84). — 

 In this account, previously noted from another source (B. S. R., 34, p. 844), 

 it is stated that native and imported cottons behaved alike as regards shedding. 

 The nature of the influence of sunshine and humidity was not determined. Seed 

 were preserved from a plant which retained all its blooms and ripened aU its 

 bolls, with a view to breeding a variety resistant to the extreme conditions and 

 quick changes prevalent in this region. 



Onion mildew, H. Bun {Rev. Hort. [Parish, 88 {1916), No. 9, pp. Ul, lJf2).— 

 A mildew disease of onions, studied since 1913, is said to have been due to 

 Peronospora schleideni, though Macrosporium parasiticum sarcinula was often 

 present, and apparently took a certain part in the alteration observed. For the 

 protection of plants from attack, the author suggests the use of Bordeaux mix- 

 ture made up of 3 per cent copper sulphate and 2 per cent lime. 



Some potato problems, P. R. Cowan {Ann. Rpt. Quebec Soc. Protec. Plaiits 

 letc], 8 (1915-16), pp. 59-6S). — Noting the growing importance of disease as 

 affecting returns from potato culture in Canada, the author discusses varietal 

 susceptibility and the symptoms of the various potato diseases. The several 

 means of control considered effective are outlined. 



Cryptogamic diseases of sugar cane, R. Averna SACciL {Bol. Agr. [Sao 

 Paulo], 11. ser.. No. 8 {1916), pp. 610-641, figs. 27).— This is a condensed ac- 

 count of information collected during several years regarding sugar cane dis- 

 eases as related to Schizophyllum commune {S. alneum), Valsaria subtropica, 

 Linospora sacchari, Leptosphceria sacchari, Euryachora sacchari, Cytospora 

 sacchari, Nectria sp., Otthia sp., Fusarium sp., Vermicularia sacchari, Colletotri- 

 chum falcatum, Lasiodiplodia theobromw, Coniothyrium sacchari, Phyllosticta 

 sp., Dendrophom^a saccharicola, Sphwropsis pseudodiplodia, and Cladosporium 

 graminum. 



Pathology and physiology of tobacco in the Crown lands, H. Jensen et xl. 

 {Proefstat. Vorstenland. Tabak [Dutch East Indies], Meded. 5 {191S), pp. 7-78, 

 122-lSO, 131, 197, 198, pis. 8).— These selections include the botanical and phyto- 

 pathological portions of a somewhat extended report embodying materials taken 

 by the author from his own work and from that of M. Raciborski, O. de Vries, 

 and M. Treub. 



Tobacco diseases, or causes thereof as dealt with, include Phytophthora 

 nicotianw (here considered as possibly identical with P. infestans) , gummosis 

 (bacterial), leaf mosaic, tjakar, various fungi, nematodes and other animals, and 

 diseases of undetermined causation. The abnormality of the flowers, character- 

 ized by their turning or remaining green, mutants with double blooms, three- 

 parted seedlings, the influence of light on germination, and the influence of 

 colored light on desiccation are also discussed. 



Lanas disease of tobacco in the CrowTi lands, H. Jensen {Proefstat. Vors- 

 tenland. Tabak [Dutch East Indies], Meded. 1 {191S), pp. S5, pis. 5). — Having 

 made a study of a disease supposedly identical with that reported by J. Van 

 Breda de Haan (E. S. R., 8, p. 237) as due to a fungus which that author de- 

 scribed as a new species under the name Phytophthora nicotiance, the present 

 author distinguishes between this disease and one characterized by a gummosis 

 (but showing a somewhat similar leaf wilt) by employing rather arbitrarily for 

 these two diseases the Javanese terms lanas and lier, respectively. 

 16179°— 17— No. 6 5 



