FACTORS AFFECTING SEASONAL ACTIVITIES. 



13 



centigrade-liour-unit represented in such amounts is 9/1600, 

 and of Fahrenheit-hour-units 81/8000. The number of hour 

 units is therefore to be found by simple division, -f indicates 

 temperature exposures above freezing; — below freezing. 



THERMOGRAPHIC OBSERVATIONS IN N. Y. BOT. 



HERBACEOUS GROUNDS. 

 Pgfg Total Number of 



Exposure Hours 



April 9 to 16, 1900 +425 149 



— -H 19 



April 16 to 2i +9-50 168 



April 23 to 30 +8.45 168 



April 30 to May 7 +7-75 168 



May 7 to 14 +9-45 164 



— .02 4 



May 14 to 21 11.56 168 



May 21 to 28 12.37 168 



May 28 to June 4 12.50 168 



June 4 to II 12.85 168 



June II to 18 13.00 168 



June 18 to 25 15.21 169 



June 25 to July 2 16.32 167 



July 2 to 9 16.85 168 



July 9 to 16 15.80 168 



July 16 to 23 17.73 168 



July 23 to 30 15.35 168 



July 30 to Aug. 6 14.46 168 



Aug. 6 to 13 18.86 168 



Aug. 13 to 20 15.66 168 



Aug. 20 to 27 15.27 168 



Aug. 27 to Sept. 3 16.36 168 



Sept. 3 to 10 15-84 168 



Sept. 10 to 17 13.25 168 



Sept. 17 to 24 10.21 168 



Sept. 24 to Oct. 1 12.35 168 



Oct. I to 8 13.30 168 



Oct. 8 to 15 930 168 



Oct. 15 to 22 +6.25 159 



-0.15 9 



Oct. 22 to 29 + 10.25 168 



Oct. 29 to Nov. 5 7.16 168 



Nov. 5 to 12 +4-30 156 



— .24 12 

 Nov. 12 to 19 +4.40 138 



— .41 30 



Nov. 19 to 26 +7.50 168 



Nov. 26 to Dec. 3 +2.86 146 



— .65 22 

 Dec. 3 to 10 +3-15 133 



— -71 35 

 Dec. 10 to 17 + .60 32 



—3.60 136 



