DISEASES OF PLANTS. 745 



to vegetation, some of which liave already been noted (E. S. R., 34, p. 523), 

 including siicli features as concentration, precipitation forms, soil factors, struc- 

 tural peculiarities, physiological relations, and temperature. 



Examination and estimation of the damage caused to vegetation by the 

 smoke and vapors from factories, F. Ranwez (Chem. News, 112 {1915), No. 

 2913, p. 151). — This is a note on the injuries and problems arising in connec- 

 tion with the fumes, chiefly sulphur dioxid, from industrial plants. 



A convenient casein spray, V. Vermorel and E. Dantony {Rev. Vit., Jf2 

 {1915), No. 1091, p. 448). — Directions are given for the convenient preparation 

 of a solution which is said to keep indefinitely in closed vessels. 



Powdered casein is dissolved in ten times its own weight of water, which is 

 stirred rapidly in the meanwhile and also while about the same proportion of 

 milk of lime is added. 



To make a spray which possesses both adherent and spreading qualities the 

 above preparation is added to 100 times its volume of alkaline Bordeaux mixture. 



The use of copper carbonate as a fungicide, G. P. Darnell-Smith {Agr. 

 Gaz. N. S. Wales, 26 {1915), No. 3, pp. 242, 243).— In order to avoid the possible 

 bad effects of wetting the seed wheat in treating for bunt, the use of dry copper 

 carbonate has been tested at the Wagga and Cowra experiment farms for two 

 years with good results thus far as regards both germiuability and freedom from 

 bunt. 



The method of applying the treatment was to shake up a bushel of the seed 

 wheat in a bag with 4 oz, of copper carbonate. The powder I'eadily adheres to 

 the brush of the grain, where the bunt spores mostly adhere, and to the longi- 

 tudinal groove of the seed. 



Teleutospore formation by the cereal rust fungi, G. Gassner {Ztschr. Bat., 

 7 {1915), No. 2, pp. 65-120). — Details are given of extended observations made 

 in the subtropical regions of South America on the progress of teleutospore 

 formation by Puccinia triticina, P. graminis, P. coromfera, and P. maydis, and 

 on the developmental relations between host and fungus. 



The dependence of teleutospore formation upon weather appears to be in- 

 direct and due to the part played by the weather in determining the develop- 

 mental stages of the host. P. graminis requires, in order to begin the forma- 

 tion of teleutospores, a more advanced developmental stage in the host plant 

 than do P. triticina and P. coronifera. P. maydis also depends upon the devel- 

 opmental stage of its host, as observable in varieties showing differences in de- 

 velopmental rates and in the periods required to reach the flowering stage. 



Puccinia oryzae parasitic on rice in the Ebro Delta, Spain, J. Florensa y 

 CoNDAL {Sindicato de Riegos del Delta Derecho del Ebro, la Enfermedad del 

 Arros {Puccinia orysw). Tarragona, 1914, PP- 3£; abs. in Internat. Inst. Agr. 

 IRome], Mo. Bui. Agr. Intel, and Plant Diseases, 6 {1915), No. 3, pp. 469, 470). — 

 A destructive disease of rice which appeared in July, 1914, in the Ebro Delta 

 is attributed to P. oryzos. Its progress is thought to be favored by soil fatigue ; 

 high-water level ; lack of care in selection and disinfection of seed ; excess of 

 nitrogen in fertilizers deficient in phosphates, potash, and iron ; persistent 

 humidity ; cool weather during the period from germination to flowering of the 

 rice; close planting; and the presence of weeds. 



Remedial measures thus far have proved to be expensive and impracticable. 



Preventive measures recommended include the burning of all vegetation on 

 the gi'ound after the removal of the straw, which should be disinfected with a 

 4-5 per cent solution of copper sulphate or with milk of lime ; disinfection of 

 the soil with lime or carbon disulphid ; maintenance of a low water level (not 

 over 7 or 8 in. ) ; use of resistant varieties of rice, with constant selection there- 



