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(11) Hintikka. T. J. 
1929 Uber die Verbreitung des Kartoffelkrebses in verscheidenen 
Landern sowie uber einige klimatischen Faktoren der ver- 
seuchten Gebiete. (On the distribution of potato wart in 
different countries and on some climatic factors of the in- 
fested areas) . Vallion Maataloukoetoiminnan Julkaisuja 23, 
102 pp. 11 maps, 1929. (Finnish with Germany summary) (Ab- 
stract in R. A.M. 12: 50-52. 1933) 
Immune vars . listed with countries of origin. Discus- 
sion of genetics, variability of susceptibility in different 
countries, etc. Effects of soil, light, moisture, etc.; wet 
localities seem to favor disease, but in Sweden disease occurs 
in comparatively dry areas. Coldest European centers of 
infection in Finland and Sweden lie within isotherms 3° 
to 4° C, warmest at 20°, south of which point wart occurs 
only in mountains or in rainy districts. 
(12) Hunt, N. Rex. O'Donnell. F. G. , and Marshall, Rush P. 
1925 Steam and chemical soil disinfection with special refer- 
ence to potato wart. Journ. Agr. Res. 31: 301-363. Aug. 
15, 1925. 
This paper gives the results of experiments in treat- 
ing soil to eliminate wart, by the use of steam alone, of 
chemicals alone, and of steam and chemicals combined. It 
also gives the results of studies on soil penetration by 
steam heat and by chemicals and a discussion of potato growth 
in chemically treated soil. (Copies of this paper are avail- 
able.) 
(13) Kohler, E. 
1931 Weber das Verhalten von Synchytrium endobioticum auf 
aufalligen und widerstands-fahigen Kartoffelsorten. (On 
the behavior of Synchytrium endobioticum on susceptible and 
resistant potato varieties.) Arb. Biol. Reichsanst, fur 
Land - und Forstwirtsch . 19: 263-284, 1931. (Abstr. R.A.M. 
11: 69-70. 1932) Author differentiates following grades of 
infection: 
1. All or nearly all sori fail to develop. 
2. Most sori abortive, intact ones on upper infected leaves 
and portions of stem. 
3. Most sori intact on upper infected leaves and mid-stem 
region of full shoots; conspicuous necroses restricted 
to stem base and lower leaves. 
4. Sori predominantly intact; extensive necroses almost all 
on lower leaves. 
5. Necroses barely perceptible, but all or nearly all sori 
develop completely. 
Mode of infection same for susceptible and resistant varieties 
and number of successful penetrations same. Death of parasite 
