236 L. R. JONES 



5° and 40°C. He will publish the final outcome later, but the 

 results to date show that this method will yield data ol much 

 interest to the physiologist as well as the pathologist. 



The satisfactory interpretation and practical application of 

 such results is, however, dependent upon securing reliable and 

 comparable field data over a wide range of territory, north, south, 

 east and west. We, as phytopathologists, should therefore be 

 ready to cooperate in any way practicable in the soil temperature 

 survey which is being organized under the leadership of the 

 Ecological Society of America. It should be a further stimulus 

 in this endeavor that Russian plant pathologists have already 

 inaugurated plans for a similar survey in their territory (21) 

 and possibly international cooperation may follow any success 

 in such national undertakings. 



LITERATURE CITED 



(1) Smith, E. F. Bacteria in relation to plant diseases 2: 36, et seq. 1911. 



(2) Jones, L. R. and Oilman, J. C. The control of cabbage yellows through 



disease resistance. Wis. Agr. Exp. Sta. Res. Bui. 38. 1915. 



(3) Livingston, B. E. Physiological temperature indices for the study of 



plant growth in relation to climatic conditions. Physiol. Researches 

 1:399. 1916. 



(4) Oilman, J. C. Cabbage yellows and the relation of temperature to its 



occurrence. Ann. Mo. Bot. Gard. 3: 1916. 



(5) TisDALE, W. H. Relation of soil temperature to infection of flax by Fu- 



sarium lini. Phytopathology 6: 412. 1916. 



(6) Orton, W. a. Environmental influences in the pathology of Solanum 



tuberosum. Jour. Wash. Acad. Sci. 3: 180. 1913. 



(7) Orton, W. A. Potato wilt, leaf roll and related diseases. U. S. Dept. 



Agr. Bui. 64. 1914. 



(8) Link, O. K. K. A physiological study of two strains of Fusarium in their 



causal relation to tuber rot and wilt of potato. Bot. Oaz. 52: 169. 

 1916. 



(9) Humphrey, H. B. Studies on the relation of certain species of Fusarium 



to the tomato blight of the Pacific Northwest. Wash. Agr. Exp. Sta. 

 Bui. 115. 1914. 



(10) Jones, L. R. The damping off of coniferous seedlings. Vt. Agr. Exp. 



Sta. Rept. 20: 342. 1908. 



(11) GiFFORD, C. M. The damping off of coniferous seedlings. Vt. Agr. Exp. 



Sta. Bui. 157. 1911. 



(12) WoLLENWEBER, H. W. Pilzparasitc Wilkekrankheiten der Kulturpflanzen. 



Ber. d. deut. bot. Gesell. 31: 17. 1913. 



