Mar. us, ros Dissemination of Chestnut-Blight Fungus 505 
_In the night of September 18 a rain of 0.68 inch was recorded, the 
time of cessation being the next morning before 3.45. Fog again pre- 
vailed all day September 19 and a noticeable spray fell until 5.38 a. m. 
and began again after 2.41 p.m. Ascospore-trap tests (Tables XII and 
XVII) showed that in 10 out of the 17 traps examined there was spore 
expulsion after 7.35 a. m. Of the eight plates exposed prior to this 
time but two yielded colonies of this Endothia. The first three plates 
were exposed in an open field at considerable distances from the trees 
(fig. 2, stations 41, 42, and 43) in the same direction toward which the 
wind was blowing, but no spores of E. parasitica were caught. These 
negative results may be accounted for by the action of the falling mist. 
Later in the day four exposures at various intervals yielded one colony 
each of the chestnut-blight fungus. 
TaBLE V.—Record of exposure plates made on September 20, 1913, at West Chester, Pa.a 
Wind. 
Number of Number of 
Plate Time. Length of| Station bacteria aout. a colonies of 
a Se No. Divection, Miles per ae. of fungi. Letra 
‘| hour. ; 
Minutes. 
5041 | 5.50a.m..... 16 44| NE. 2.6 ° 12 10 
5042 | 5.55a.m..... 13 45 ae 2. : ° 9 7 
5043 | 5.50a.m..... 14 4 ° z ° Io 4 
5044 | 6.03 a. m..... 1234 51] NE. 2.6 ° 23 22 
5045 | 6.14a.m..... 12% 47 | NE. 2.6 ° 14 II 
5040 i8a.m..... 15 48 au a8 ° 9 Z 
04, 20a.m..... 15 49 : “ ° II 
ane 6.40a.M..... 1314 II ae Z 2 ° 6 6 
104! 07 a.m..... 11% I 2. ° 9 7 
tare ae Ay Mvesds 13 9| ENE 2.6 ° 6 3 
50st | 7.40a.mm..... 1634 se ele 2.6 ° 6 I 
052 | 8.24a.m..... 10 2.5 ° I I 
pee g.09 a.m..... 13% 8| ENE 2.5 ° I I 
5054 | 9.374. m..... 14% 27 | ENE 3.0 5 II ° 
5055 | 10.01 a. m.. me 6 me 2.4 ° 2 ° 
056 | 10.32 a.m.. 9% 10 7 z4 ° 3 ° 
ao II.09 a. m.. ro 29 E. 2.6 © 12 ° 
5058 | 11.44 4. m.. 11% 26 E. 2.6 co) 6 ° 
5059 | 12.08 p. m.. Io 10 E. 2.7 ° 2 ° 
5060 | 1.05 p.m... 144 30 E. 2.7 ° 2 ° 
506r | 1.35 p.m..... 13% II E. 2.5 ° I ° 
5062 | 2.08 p. m..... 1434 10 E. 2.5 ° 19 ° 
5063 | 2.36p.m..... 15% 8 E. 2.7 2 4 ° 
5064 | 3-09 p. m.. 13% 9 E. 27 ° I ° 
5065 | 3-42 p.m..... 14 29 E. 2.7 ° 2 ° 
5066 | 4.06 p. m..... 18 23 E. 2.3 ° 4 ° 
.41p.m..... 124 12 | ESE. 2.7 ° 4 ° 
5067 | 4-41 p 
5068 | 5.25 p.m..... 12 12| SE. 2.7 3 4 ° 
@ Rainfall, night previous, 0.09 inch. Time of cessation, 3.25 to 3.55 a. m. 
While there was but 0.09 inch of rain in the night of September 19, 
very important results were obtained on September 20. Tables II and 
V give the results secured. Fog prevailed during the entire day, and the 
bark on the trees dried very slowly. Examination of the ascospore traps 
_ to determine the duration of spore expulsion (Tables XIII and XVII) 
showed that in 8 out of 19 the perithecia were active after 9.18 a. m. 
