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 

 4 a. 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 1 1 

 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, iQl3,at West Chester, PaA 



Plate 

 No. 



4787 

 4788 

 4789 

 479° 

 4791 

 4792 

 4793 

 4794 

 4795 

 4796 



4797 

 4798 



4799 

 5000 

 5001 

 5002 



5003 

 5004 



5°oS 

 5006 



S007 

 5008 

 5009 

 5010 

 5011 

 5012 

 5013 

 S014 



Time. 



5.51 a. m. . . 

 5.54a. m.. . 

 6.00 a. m. . . 



6.19 a. m. . . 

 6.35a. m.. . 



6.48 a. m. . . 

 6.54 a. m. . . 

 7.02 a. m. . . 

 7.25 a. m. . . 

 7.34a. m... 

 7.58a. m... 

 8.04 a. m. . . 

 8.29 a. m. . . 



9.20 a. m. . . 



9.49 a. m. . . 

 10.21 a. m. . 

 10.54 a. m. . 

 11.25 3- ■"■ ■ 

 II. 51 a. m. , 



1. 14 p. m. ., 



1.44 p. m. . 



2.15 p. m.. 

 2.46 p. in. . 

 3.19 p. m. . 



3.45 p. m.. 



4.16 p. m. . 

 4.44 p. m.. 

 5.23 p. m.. 



Length of 

 exposure. 



Minutes. 

 10 



10 



13 

 II 

 II 

 12 



loK 



II 



II 



loX 



loK 



10 



II 

 loX 



12 

 II 



iiK 



r3K 

 loX 



loX 



15 



II 



II 



13K 



iiX 



loK' 



Station 

 No. 



3 



15 



6 



I 



II 



3 



4 



16 



3 

 13 

 IS 



9 

 17 



I 



3 

 6 



15 

 33 



3 



26 

 21 

 22 



6 



33 

 21 



2S 



23 



I 



Direction. 



NW. 

 NW. 

 NW. 

 NW. 

 NW. 

 NW. 

 NW. 

 NW. 

 NW. 

 NW. 



W. 



W. 



W. 



W. 



W. 



w. 

 w. 

 w. 

 w. 

 w. 

 w. 

 w. 

 w. 

 w. 

 w. 

 w. 

 w. 

 w. 



Miles per 

 hour. 



Trace. 



Trace. 



Trace. 



Trace. 



Trace. 



Trace. 



Trace. 



Trace. 



Trace. 



0.4 



•7 



■7 



•7 



1. I 

 1.8 

 2.8 

 2.8 

 3-7 

 3-7 



2. 2 

 2.8 

 1.8 

 I. 2 

 I. 2 



•9 

 •9 

 . 2 

 . I 



Number of 

 bacteria 



and 

 yeasts. 



6) 

 6) 



Total 

 number 

 of fungi. 



Niunberof 

 colonies of 

 Endothia 

 parasitica. 



20 



58 

 39 

 59 

 67 

 16 



32 

 23 

 3° 



8 



II 



2 



I 



8 



25 

 10 



19 

 12 



13 

 17 



7 



10 

 12 

 12 

 16 



I 

 21 



3 



16 



9 



4 



5 

 2 

 2 

 o 

 2 

 I 

 I 

 o 

 o 

 o 

 o 

 o 

 o 

 o 

 I 

 o 

 o 

 o 

 I 

 o 

 o 

 o 

 o 

 o 



a Rainfall, night previous, 0.26 inch. Time of cessation, prior to 4 a. m. ^ Nimicrous. 



