UNITED STATES DEPARTMENT OF AGRICULTURE | 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. PROFESSIONAL PAPER January 15, 1917 
ENDOTHIA PARASITICA AND RELATED SPECIES. 
By C. L. Suear, Pathologist, and Net. E. Srevens,’ Pathologist, Fruit-Disease 
Investigations, and Rusy J. TrtrEr, Scientific Assistant, Office of Investiga- 
tions in Forest Pathology. 
CONTENTS. 
Page. Page. 
RRONOMI YS ocpcscncwencncseneciwayanetenn is 1 | Physiology—Continued. 
Introduction ........-------.-e0-s sees ees 1 Distribution of the species of Endothia.. 48 
The genus Endothia..........-..-....--- 3 Discovery. of Enéothia parasitica in 
The species of Endothia................. 13 UPI. nos oniocawbsengeemodncn Weems 54 
Morphology and development.........../.-. 22 Discovery of Endothia parasiticain Japan 58 
Mycehum' cise oeecvencnaresciansie cna 22 Present distribution of Endothia para- 
SOM aba ssc jade gsaersesinsedewesmenoices 23 Siticain America.......-......22.2-.-- 59 
Spore measurements..........-..---.-.-- 30 Host relations of the species of Endothia. 59 
Physiology wise senweavin seasee staat pediciwen 26") Summary... siscccwasa cubs sn aeactyvseasecves 74 
Cultural studies...............2..2.-2--- S6 | Literature itd... cccsenceacareaconmsiannes.s 77 
TAXONOMY. 
INTRODUCTION. 
The discovery of a serious canker of the chestnut in the New York 
Zoological Park in 1904, by Merkel (49),? first attracted the atten- 
tion of pathologists and foresters to what has proved to be one of 
the most serious epidemics of a plant disease ever known in this 
country. 
The fungus which was found associated with these cankers (PI. 
I and PI. II, fig. 1) and soon demonstrated experimentally to be 
their cause Was described by Murrill (57) in 1906 as a new species 
of Diaporthe (D. parasitica). Search for the fungus in other places 
in New York and vicinity soon showed that it was already estab- 
lished and apparently rapidly spreading. Investigations which 
have been continued and extended from year to year have shown 
i igati i hology. 
1 Formerly Pathologist, Office of Investigations in Forest Pat ; 
2 Serial numbers in parentheses refer to ‘“ Literature cited,” at the end of the bulletin. 
Nors.—This bulletin is of value to botanists, especially plant pathologists and mycolo- 
gists, and’ to all persons who are interested in the study of chestnut blight. 
43737°-—Bull. 380—17——1 
