S. a. Paine 71) 



which was thoroughly characteristic of the disease in the original tuber, 

 the organism has again been isolated. Occasionally inoculations of potato 

 broth with pieces of the original diseased tissue have failed entirely to 

 produce turbidity in the broth. This sterility is believed to be due to the 

 weak parasitism of the causal organism, the plant tissue having by cork 

 formation confined the parasite witliin narrow limits in which it has died 

 out during the winter. 



The symptoms of the disease here dealt with correspond exactlv with 

 those described by Horne(3) for "Internal Disease" and by Mayer (i), 

 Frank, A. B.(i), Sorauer and Rorig(5) and Frank, B.(2) under the names 

 "Buntwerden," "Eisenfleckigkeit," "Buntheit," or "Stockfleckigkeit." 

 There seems little doubt that these workers have described one and the 

 same disease. All the German workers have come to the conclusion that 

 the disease is not of parasitic origin and have sought for the cause in 

 the physiological condition of the soil. Home alone suggests that further 

 search for a parasite might be advisable. The question of the identity 

 of their disease with the one dealt with in this paper, for which the name 

 "Internal Rust Spot" is suggested, is therefore of some considerable 

 interest. Further discussion of this relationship and a full description of 

 the causal organism of the "Internal Rust Sj^ot" disease are reserved 

 for a later paper. 



REFERENCES. 



(1) Frank, A. B. Das Buntwerden oder die Eisenfleckigkeit der KartolTcIu. Kainjf- 



buc.h q. (1. SchddlingR unserer Feldfriichte, Berlin, 1897, s. 211. 



(2) Frank, B. Untersuchungen iiber die verschiedenen Erreger der KartofTcJfaulc. 



Ber. d. deutsch. hot. Gesellschajt, Bd. xvi, 1898, s. 287. 

 (.'i) HoRNE, A. S. The Symptoms of Internal Disease and Sprain (Streak Disease) ni 



Potato. Journ. Agric. Sci. vol. in, 1910, p. 323. 

 (4) JIayer, a. Die Ringkrankheit oder Eisenfleckigkeit der Kartoffel. Jourii. fiir 



Landwirtschaff, Bd. Lv, 1907, s. 301. 

 (o) Sorauer, P. u. Rorig, G. Die Eisenfleckigkeit. PJlutizenscJndz, Beriin, 1910, 



.«. 154. 

 (0) S.MiTH, E. F. Bacteria in Relation to Plant Diseases. Washington, D. C. 1914, 

 vol. ni, p. 175. 



