- 7 - 
variety." The variety was Preussen. Spores reacy to germin- 
ate at about 5% a month" .... so that in about iwo years all 
would presumably have germinated." Stimulants have no effect 
after a time, so treated and untreated spores might have the 
same percentage germinated after 6 mos. 
(6) Ducomet, V. and Foex, E. 
1928 Essais effectues en 1927 au champ d' experiences etabli 
par 1' Institut des Recherches Agronomiques a Russ-Kersbach 
(Bas-Rhin) en vue de 1' etude de la maladie verruqueuse (Syn- 
ch y trium endobioticu m (Schilb.) Perc.) de la pomme de terre 
(Trials conducted in 1927 on the experimental field laid out 
by the Agricultural Res. Inst. etc. for investigation of wart) 
- Comptes rendus Acad, d' Agric. de France 14: 442-45. 1S28. 
(Abstr. in R.A.M. 7: 596, 1928.) 
Wart infection and resistance of potato varieties. - 
Studies showed infection was transmitted (1) thru the soil to 
a depth of 50 cm., (2) thru soil of field infected 2 yrs. 
before, (3) thru sweepings from a cellar where infected 
potatoes had been stored, even tho disinfected with lime, 
(4) thru refuse of a village in the infected zone, (5) thru 
soil of a meadow irrigated with water from infected zone, 
(6) thru soil adhering to turnips dug from a field infected 
in the previous year. Air infection spread tests were nega- 
tive. 
(7) Ducomet, V. and Diehl, R. 
1936 La galle verruqueuse de la Pomme de terre (Synchytrium 
endobioticum (Schilb.) Perc). Mise au point de la question 
de la resistance des varieties. (A critical summary of the 
question of varietal resistance.) - Ann. Epiphyt., N. S. i, 
pp. 57-79, 2 maps, 1936. (Abstract in R.A.M. 15: 601-2. 
Sept. 1936.) 
Notes on introduction into France and present distribu- 
tion there. "In the north of France new infection centres 
are due more to the introduction of foreign tubers than to 
the spread of already existing diseased areas." (R.A.M.) 
"It appears that under certain conditions favorable to tissue 
proliferation some reputedly resistant varieties may be very 
slightly attacked and serve as a source of spread." (R.A.M.) 
"A study of tuberiferous species of Solanum showed that types 
susceptible to S. e ndobioticu m are present in all chromosome 
Groups." (R.A.M.) 
(8) Esmarch, F. 
1927 Untersuchungen zue Biologee des Kartoffelkrebses. II 
(Investigations on the biology of the potato wart.) Angew. 
Bot. 9: 88-124. 1927. (Abstr. in R.A.M. 6: 635-6, 1927 - see 
also R.A.M. 5: 577-8, 1S26 & R.A.M. 3: 477. 1924.) 
