- 14 - 
cropper in the region; Parnassia was also very resistant to wart 
disease, but is a poor producer in the neighborhood of Lenin- 
grad. (From R.A.M. abstract - Later articles in R.A.M. say- 
wart is not in U.S.S.R.) 
(20) Selaries, P. & Rohmer, G. 
1936 La maladie verruqueuse de la Pomme de terre en Alsace. 
(Potato wart disease in Alsace.) - Ann. Epiphyt. E. S. i, 
pp. 23-55, 26 figs., 1936. (Abstr. in R.A.M. 15: 601. Sept. 
1936.) 
Variety resistance tests show some resistant varieties 
diseased at times in field. Laboratory infection tests 
show some vars. resistant in field readily diseased, but 
infection not apparent. Resting stage produced in lesions 
on resistant vars. as shown by microscope examination. 
(21) Weiss, F., Orton, C. R., and Hartman, R. E. 
1923 Investigations of potato wart. U. S. Dept. Agr. Dept. 
Bui. No. 1156, pp. 1-21. May, 1923. 
I. The varietal and species hosts of Synchytrium en - 
dobioticum , by Weiss and Orton. 
II. The adaptability and use of wart-immune varieties 
of potato in the quarantined areas of Pennsylvania. 
By Hartman. 
III. The stability of wart immunity, by Weiss. 
(22) Weiss, F. and Brierley, P. 
1928 Factors of spread and repression in potato wart. U. S. 
tech. bull. No. 56. March, 1928. 
This paper includes proof that apparently healthy po- 
tatoes may bear adhering spores and become infected when 
planted. Agencies of spread distribution of wart spores in 
surface 8 inches of soil only, duration of infectiousness 
of soil, tomato hosts, resistance of spores to heat and to 
seed disinfectants are discussed. 
