440 CONNECTICUT EXPERIMENT STATION REPORT, IQI2. 
ConbENsep ResutTs or INOCULATIONS WITH ENDOTHIA 
GYROSA AND ENDOTHIA GYROSA PARASITICA. 
Inoc. | Failed Took 
(No.) (No.) (No)| 4 
E. g. parasitica from Cast. on Cast. dent. seedl...| 177] 86 | 91 | 51 
oe as a oe ae oe te ce sprts. er 55 14 4t 75 
Eien ie - ‘© «Quer. sp. seedl...] 12] 12 fs) o 
ae “ce ce “et ot “se “sé ae sprts. se 7 re) 7 roo 
oe oe ‘© Querc. on Cast. dent. seed]. ..| 25 21 4 16 
o ce 66 at 6c ray oe “ac sprts. aes 16 1611 oO ° 
ne aes tt 7 ‘© ** Quer. sps. seedl, ..| 20 | 20 ° ° 
se ce “ee ee oe te fe as sprts. seen 12 7 5 42 
E. gyrosa “Cast. on Cast. dent. seedl...| 15 15 oO fs) 
ae ae ae oe ot ee ce sprts. re 18 18 re) fe) 
Ke ae “e se «Quer. sps. seedl. .. 5 5 o oO 
oc as ot ac ae ce ae sprts. eis rey oO re) re) 
es ne ‘© Querc. on Cast. dent. seedl...| 82] 81 I L 
ae oe ee “é oe ae ae sprts. oe 4 3 I 25 
se ae os «Quer. sp. seedl... 5 5 {o) oO 
46 ae “et +e +6 oe it} sprts. sate 19 1g fe) oO 
Checks..... ue det vee taeeauven ie sauacscenenss eis on all Castanea..| 113 | 113 oO ° 
Checks........ sha cavunsb rion ienatauaeenetenets on all Quercus..| 15 15 oO oO 
1Kept moist. *Kept dry. **One dry, one moist. # Culture originally 
from conidial spores. ‘Culture from ascospores. * Trees ridged to produce 
drought conditions. °®Trees unridged. ‘Inoculated above and below knife 
girdle. *Cut above and below knife girdle, but not inoculated. * Stem in- 
oculated underground. Stem cut underground, but not inoculated. "If 
done earlier in the season, possibly some would have taken. These foot- 
notes apply chiefly to large table; see column ‘‘ Host Inoc.” for numbers. 
on August 4, 1909, which produced only 50 per cent. infection 
as against 100 per cent. produced by a culture over two years 
younger obtained from Washington, D. C., on January, 2, 1912. 
Both of these were of the same spore age, and inoculated into 
chestnut seedlings at the same time and place. 
That the age of the spores used affects their virulence is 
apparently shown in a number of our inoculations. We used 
spores from cultures that had been made all the way from 20 to 
100 days, in a few cases even 250 days. These spores were always 
somewhat moist when used, and though possibly some of them 
were too old to germinate, there must have been others that 
were not, since we have renewed cultures not infrequently that 
were 100 days old, and in one case a culture that was-399 days 
old. Our inoculation tests apparently indicate that the younger 
