4 BULLETIN 360, U. S. DEPARTMENT OF AGRICULTURE. 
infection, badly stunted yellow pine, larch, Douglas fir, and lodge- 
pole pine growing in the open and on otherwise good sites often — 
measure less than 6 inches at the stump, but show ages ranging from | 
100 to 200 years or more. Young seedlings, if not killed outright 
within a COTTE TE short time after infection, usually show a 
PTET | 
se re CACC 
WELLE VEAL 
ead AAD Gaeta NLL 
Se a a a 
rCACEEPTLVLECELLVACCUA CLEELPEECEL EEE 
HEUTE CORe een Mp 
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AVERAGE ANNUAL GROWT/L /NCHTES 
-OF 
-O2 
-O/ 
1874 1830 S885 1890 S895 1900 19OS 1HO 4/5 
FEARS 
Fic. 2.—Graphs showing the average annual growth (in inches) for 40 years (1874 
to 1913, inclusive) of 50 trees of yellow pine heavily infected with mistletoe, com- 
pared with 50 uninfected trees of the same species for the same period. A, heavily 
infected trees: Average-age class, 100 years; average height, 49.5 feet; average 
diameter, breast high, 18.2 inches. B, Uninfected trees: Average-age class, 100 
Aare 
years; average height, 77.2 feet; average diameter, breast high, 22 inches. 
marked falling off of the foliar surface of the parts uninfected and 
finally succumb to the attack (fig. 5). Very frequently young in- 
fected seedlings develop into ball-like brooms. 
Table II shows the youngest age class of five hosts at which mistle- 
toe infection has been found to occur and the locality where the 
observations were made. 
