1917] DISEASES OP PLANTS. 47 



disease, for the first method of infection soaliing the seed In copper sulphate or 

 formaldeliyde solution is recommended, and for the second method of infection 

 either early sowing of wheat before the thrashing season has begun or late 

 sowing after the smut spores scattered over the soil have germinated. In these 

 investigations an automatic sprinkler has been devised and perfected by the 

 station for use in connection with thrashing outfits. 



[Plant diseases in 1915] (Phytopath. Lab. "Willie Commelin Scholten" 

 Jaarver. 1915, pp. 18). — The report on plant diseases and investigations deals 

 with injuries to fruit trees due to Hymenomycetes, anthracnose of flax, narcissus 

 diseases, Botrytis on flowers, potato mosaic, and Rhizoctonia (Hypochnus) 

 solani on potato. 



Plant protection, F. G. Stebleb {Landw. Jahrb. Schtoeiz, SO {1916), No. 1, 

 pp. 20-23). — This is a very condensed account dealing with the spring condi- 

 tion of cereals; diseases and protection of cereals, potatoes, beets, and legumes; 

 and various wild plants, or weeds, as noted at the Zurich Experiment Station. 



Studies in tropical teratology, J. C. Costerus and J. J. Smith (Ann. Jard. 

 Bot. Buitenzorg, 8. ser., U (1916), pt. 2, pp. 83-94, pis. 5).— The authors have 

 here described a number of monstrosities, including witches' broom, as observed 

 in plants representing a wide range of classification, the specimens examined 

 having been from Buitenzorg. 



Studies in the physiology of parasitism. — II, Infection by Botrytis cinerea, 

 V. H. Blackman and E. J. Wel&bord (Ann. Bot. [London], SO (1916), No. 119, 

 pp. 389-398, pi. 1, figs. 2). — This is in continuation of the series of Contributions 

 begun by Brown (E. S. R., 34, p. 847). 



Ticia faba was studied regarding its capacity for infection by B. cinerea. 

 Infection was readily accomplished when the leaf surface was moistened with 

 turnip juice. The germ tube soon develops a mucilaginous layer by which it 

 appears to be so firmly anchored to the cuticle that its tip can bend in and pene- 

 trate the cuticle with a peglike outgrowth, apparently by mechanical pressure 

 alone. No swelling or other change in the cuticle or in the underlying epidermal 

 layers prior to penetration has been observed, but as soon as the cuticular layer 

 is passed a swelling of the subcuticular layer occurs, showing enzym action. 

 Penetration of the cuticle by the germ tube was not preceded by death of epi- 

 dermal cells, but swelling of the latter preceded the disorganization of the 

 protoplast. No microscopic evidence was found for the secretion of a special 

 toxic substance other than the enzym for dissolving the cell wall. 



Studies in the physiology of parasitism. — III, On the relation between the 

 " infection drop " and the underlying host tissue, W. Brown (Ann. Bot. 

 [London], 30 (1916), No. 119, pp. 399-406).— It is stated that the results of this 

 purely physiological study, as here detailed, are in exact agreement with the 

 results of the microscopical study, as above noted, by Blackman and Welsford. 



On the osmotic pressure of the tissue fl.uids of Jamaican Loranthacese 

 parasitic on various hosts, J. A. Haeeis and J. V. Lawrence (Amer. Jour. 

 Bot., 3 (1916), No. 8, pp. 438-455, figs. 2). — Data gathered from a study of ma- 

 terials obtained in 1915 near Cinchona, in the Blue Mountains of Jamaica, 

 employing seven species of Loranthacese in three genera parasitic on nineteen 

 species of host, are presented. The authors claim that stem sap from the 

 leafless species of Dendrophthora has a lower osmotic pressure than that from 

 leaf tissue of Phoradendron or Phthirusa, also that the osmotic pressure of 

 the sap from the chlorophyll-bearing tissue of the parasite is almost always 

 greater than in that from the mature leaves of the host. 



The fungicidal properties of certain spray fluids, J. V. Eybe and E. S. 

 Salmon (Jour. Agr. Sci. [England], 7 (1916), No. 4, pp. 473-507).— In the hope 

 of ascertaining to what particular factor the fungicidal value of alkaline sul- 



