Number of Micro-organisms falling per square foot per minute. 
{BULLER AND Lown] 


8000 — she black lines join the Experimental points. 
See The pecked lines join the Averages for each month. 
—.—:-—-—:— The dot-and-dash lines join the Temperatures in Centi- 
grade degrees observed at the time of each Experi- 
7000 ment. 
AIR COLLECTED ON THE CAMPUS OF THE UNIVERSITY OF MANITOBA, WINNIPEG. 



sreesesseessesses The dotted lines join the monthly Averages of Tempera- 
tures observed at the time of each Experiment. 
6000 

[PLATE 11.] 













5000 








4000 







































Blasco 




NEAL TTT 



[ 
NY = 





[M 
| oS 
[= = | 
et a — (zal 
Sie Sai 

6 13 20 27 4 11 18 25 1 8 15 22 29 6 13 20 27 3 10 17 24 31 7 14 21 28 5 12 19 26 
APRIL May JUNE JULY Ava. Sepr. 
1908 

= 
EBD ars 







Ocr. 
2 

9 16 23 30 7 14 21 28 4 11 18 25 1 8 15 22 1 8 15 22 295 
Nov. 
Dec. 
1908 
JAN. 
1909 
Fes. 
Marcu 
1909 
2 OPBIAYUIH 2101199 
