1922] WILLAMAN & DAVISON—PLANT DISEASES 109 
is the sound tissue. This is no doubt due to loss of dry matter by 
respiration in the rotted samples. 
2. The resistant varieties are conspicuously higher in crude 
fiber than the susceptible. The quality and quantity of the 
structural elements of the tissues no doubt are important factors 
in their resistance properties. The ash, nitrogen, CaO, and ether 
extract are lower in the resistant varieties, but not sufficiently so 
to constitute limiting factors in the nutrition of the invading 
parasite. 
3. As the ripening of plums proceeds, there is a decrease in the 
ash, nitrogen, and calcium content, due probably to storage of 
carbohydrates and acids, 
DIVISION OF AGRICULTURAL BIOCHEMISTRY 
MINNESOTA AGRICULTURAL EXPERIMENT STATION 
St. PAu. 
LITERATURE CITED 
1. Association of Official Agricultural Chemists. Methods of Analysis. 
Baltimore. 1916. 
. Kennepy, C., A capecagiuanes of = i oa method for crude fiber. 
Jour. Ind. and Eng. Chem. 
Nu 
3- MitcHett, J. H., Report on nor lant constituents. Jour. Ass. 
Official Agric. Chemists 42391-3904. 
4. VALLEAU, W. D., Varietal ae : ane to brown rot. Jour. Agric. 
Res. 5: 365-395. 1915. 
5. WiLiaMAN, J. J., Pectin relations of Sclerotinia cinerea. Bor. GAz. 70: 
221-229. 1920. 
6. WILLAMAN, J. J., and Sanpstrom, W. M., Biochemistry of plant diseases. 
J 
III. Effect of the fungus Sclerotinia cinerea on plums. Bor. Gaz. 73:287- 
307. figs. 7. 1922. 
