effect of the endrot fungus on cranberries 24i 
Comparison of Chemical and Histological Observations 
The chemical analysis of sound cranberries and of those affected by the 
endrot fungus shows that the only marked difference is that rotten berries 
contain considerably less sugar. It is apparent that the endrot fungus 
uses the sugar contained in the cells of the cranberry; this was to be ex- 
pected from the fact that the hyphae frequently penetrate the cells and 
enter the vacuoles. In view of the high acid content of the cranberry and 
of the fact that F. putrefaciens is known only on that fruit, it is interesting 
to note that there is no considerable change in the total acid content. As 
the various acids known to occur were not separately determined, the 
possibility that the fungus uses one or more of the acids and produces some 
other acid in approximately equal amounts, has not been eliminated. At 
least one fungus producing decay of fruits has been reported to produce 
acid, and others have been reported as using acids (see summary in 3, p. 80). 
Chemical and histological observations agree in indicating that the fungus 
has little, if any, effect on the cuticle of the berry. 
Summary 
The endrot fungus has such distinctive characters that it was possible 
to select cranberries rotted by this fungus alone. A histological study of 
those selected berries showed that the endrot fungus grows in all parts of 
the berry except the seeds and the cuticle and is able to penetrate cell walls 
and protoplasm. A chemical study showed that the sugar content of 
berries rotted by the endrot fungus is much lower than that of sound fruit. 
The fungus thus apparently utilizes these sugars. 
Bureau of Plant Industry, Washington. 
Massachusetts Experiment Station, Amherst. 
LITERATURE CITED 
1. Franklin, H. J. Report of cranberry substation for 1914. Mass. Agr. Exp. Sta. Bull. 
160. 1915. 
2. . Report of cranberry substation for 1915. Mass. Agr. Exp. Sta, Bull. 168. 1916. 
3. Hawkins, Lon A. Some effects of the brown-rot fungus upon the composition of the 
peach. Amer, Journ, Bot. 2: 71-81. 1915. 
4. . Effect of certain species of Fusarium on the composition of the potato tuber. 
Journ, Agr. Res. 6: 183-196. 1916. 
5. Shear, C. L. Cranberry diseases. U, S, Dept. Agr. Bur. PI. Ind. Bull. no. 1907. 
6. . Endrot of cranberries. Journ, Agr. Res. 11: 35-42. 1917. 
7. Stevens, Neil E. Pathological histology of strawberries affected by species of Botrytis 
and Rhizopus. Journ. Agr. Res. 6: 361-366. 1916. 
8. . Temperatures of the cranberry regions of the United States in relation to the 
growth of certain fungi. Journ. Agr. Res. 11: 521-529. 1917. 
9. Wiley, H. W., et al. Official and provisional methods of analysis, U. S. Dept. Agr. 
Bur. Chem. Bull, 107 (revised). 1908. 
