186 MISCELLANEOUS PUBLICATION NO. 725, U.S. DEPARTMENT OF AGRICULTURE 
Wounds Yellow-poplar--Continued 
callus formation, 1286, 1289 top rot following snow dam- 
dressings, 339, 1290, 1291, age, 1596 
2096 York, H. H., 1504 
protection, nut trees, 337 Young, George Y., 412, 414, 
treatment, 1293, 1296 415, 416, 588 
Wright, Ernest, 413, 414, 418, Young, H. Gea 1934 
1160,, 1165,. 1499, 4563599724, 
1725 Zabel, Robert A., 1682 
Zak, Bratislav, 1101 
Xylaria digitata, 2176 Zemlansky, John, 1358 
Xylaris polymorpha, 2176 Zygosaccharomyces pini, new 
species, 1002 
Yellow-poplar Zythia resinae--SEE Biatorella 
decay, 971 resinae 
discolorations, 980, 1601 
UNITED STATES 
GOVERNMENT PRINTING OFFICE 
WASHINGTON : 1957 
For sale by the Superintendent of Documents, U. S. Government Printing Office 
Washington 25, D. C. - Price 55 cents 
