504 Journal of Agricultural Research Vol. III, No. 6 
Cloudiness prevailed on September 12, with traces of rain insufficient to 
cause spore expulsion. In the night less than one-tenth of an inch of rain 
fell, and subsequent examination of the ascospore traps showed that very 
light ascospore expulsion had occurred. Five plates were exposed before 
8 o’clock the next morning, but the bark was dry at the time and no 
spores were obtained in any of the plates exposed that day. Three days 
of clear, hot weather followed, and no spores were caught. Of the plates 
exposed on September 17, two yielded one colony each of the fungus. 
In the evening of September 17 a series of rains began, occurring 
usually in the night. Our most important positive results were obtained 
from tests made following these rains. Tables II and IV give the results 
of the plates exposed on September 18. Although the rain ceased before 
4a. m.,a heavy fog prevailed in the early morning, there was only a trace 
of wind, and it was more or less cloudy all day. Because of these condi- 
tions the bark of the trees was slow in drying, and examination of the 
ascospore traps (Tables XI and XVII) showed that abundant spore 
expulsion had occurred in the night and was still in progress while the 
first four exposure plates were made. A few of the traps gave evidences 
of the continuation of expulsion during the time in which the next 11 
plates were exposed. /Six of these yielded colonies of Endothia parasitica 
in varying numbers, and two exposed much later in the day also showed 
one colony each. 
TABLE IV.—Record of exposure plates made on September 18, 1913, at West Chester, Pa. 
; wine Numberof] jy 44) |Numberof 
Plate Time. Length of} Station bacteria Pre er | colonies of 
No. exposure.| No. .. | Miles per and of fungi Endothia 
Direction. hour. yeasts. " | parasitica. 
Minutes. 
4787 | 5.51 a.m..... 93% 3] NW. | Trace. 4 20 II 
4788 | 5.54a.m..... Io 15 | NW. | Trace. 6 58 16 
4789 | 6.00a.m..... Io 6| NW. | Trace. 6 39 9 
4790 | 6.19 a.m..... 13 r| NW. | Trace. b 59 4 
4791 | 6.35 a.m..... II ir | NW. | Trace. b 67 5 
4792 | 6.48 a.m..... II 3| NW. | Trace. I 16 2 
4793 | 6.54a.m..... 12 4| NW. | Trace. b 32 2 
4794 | 7.02 a.m..... 104 16 | NW. | Trace. b 23 é 
4795 | 7.25a.m..... II 3| NW. | Trace. b 30 2 
4796 | 7.34a.m..... II 13} NW. 0.4 3 8 I 
4797 | 7.58 a.m..... 10% us| W. 9 8 II I 
4798 | 8.04a.m..... 1034 9 W. ae ° 2 ° 
4799 | 8.29 a.m..... 0 17 Ww. a ° I ° 
5000 | 9.20a.m..... 1214 I W. rag ° 8 t) 
5001 | 9.49 a.m..... II 3 Ww. 1.8 ° 25 ° 
5002 | 1Q2ra.m....) rol 6 W. 2.8 5 10 ° 
5003 | 10.54a.m....| 12 15 W. 2.8 I 19 Co) 
5004 |; Il.25a.m....| 11 33 Ww. 3.9 ° 12 ° 
goo5 | Il.5ra.m....) x14 3 Ww. 3.7 3 13 I 
5006 | 1.14 p.m.... 13% 26 Ww. 2.2 I 17 ° 
5007 | 1.44 p.m 10% 21 W. 2.8 ° 7 ° 
5008 | 2.15 p.m..... 10l4 22 W. 1.8 I Io ° 
5009 | 2.46 p.m..... 15 6 Ww. 1.2 I 12 I 
5010 | 3.19 p.m..... II 33 Ww. 1.2 ° 12 ° 
501r | 3.45 p.m..... II 2I W. +9 I 16 fc) 
5012 | 4.16 p.m..... 1314 25 Ww. “9 ° I ° 
5013 | 4.44p.m..... 1% 23 Ww. 2 4 ar fc) 
5014 | 5.23 p.m..... 1034 I Ww. LI ° 3 ° 
@ Rainfall, night previous, 0.26 inch. ‘Time of cessation, prior to 4 a.m. * bNumerous. 
