526 



The Philippine Journal of Science 



1914 



Table XLII. — Temperature of undergrowth in forest of Mount Maquiling, 



Laguna Province, Luzon. 



[Degrees Centigrade.] 



Period. 



Maxi- 

 mum. 



Jan. 3 to Jan. 31. 

 Jan. 31 to Feb. 28 

 Feb. 28 to Mar. 28. 

 Mar. 28 to Apr. 25 

 Apr. 25 to May 23 . 

 May 23 to June 20. 

 June 20 to July 18 

 July 18 to Aug. 15 

 Aug. 15 Sept. 12.. 

 Sept. 12 to Oct. 10 

 Oct. 10 to Nov. 7 . 

 Nov. 7 to Dec. 5.. 

 Dec. 5 to Jan. 2.. 



Average ... 



26.9 



Mini- 

 mum. 



24.8 



18.6 



25.6 



18.9 



27.7 



19.4 



28.0 



19.4 



28.3 



20.5 



29.7 



21.7 



27.7 



20.5 



27.4 



2L1 



27.4 



20.6 



27.7 



20.8 



25.8 



19.4 



25.0 



19.4 



25.0 



19.7 



19.9 



Mean. 



2L7 

 21.9 

 23.0 

 23.8 

 24.1 

 26.1 

 23.8 

 23.3 

 23.4 

 23.6 

 22.7 

 22.0 

 21.7 



Average 

 daily 

 maxi- 

 mum. 



22.8 

 23.7 

 25.7 

 26.4 

 26.6 

 27.8 

 25.8 

 25.2 

 26.3 

 25.9 

 24.6 

 23.3 

 22.7 



23.1 



25.1 



Average 

 daily 

 mini- 

 mum. 



20.7 

 20.5 

 21.2 

 21.7 

 22.4 

 22.9 

 22.2 

 22.3 

 21.9 

 22.2 

 21.7 

 20.8 

 20.8 



2L6 



different regions in advancing growth. Livingston and Living- 

 ston '^ suggest a formula which should be useful, although, as 

 they point out, the figures in it are tentative. They assume that 

 the rate of gi'owth is unity at 40° F. and that it doubles for 

 each rise of 10° C. (18° F.) above this. The last assumption 

 is based on recent experimental work on growth and other 

 metabolic processes. If t is taken as the normal daily mean 

 temperature on the Fahrenheit scale and if u is the correspond- 

 ing temperature efficiency for growth, according to the assump- 

 tion then — 



u- 



(-40 



=2" 



The time element is taken into account by adding together the 

 efficiency indices for all of the days of the frostless season. Fol- 

 lowing this method, Livingston and Livingston have prepared a 

 chart of the temperature efficiencies in the United States. 



Temperature on Mount Maquiling is so uniform that instead 

 of calculating the efficiency for each day, we have made the 

 calculation for the average of each four-week period, multiplied 

 it by 28, and then added together the results for each period. 

 The resulting efficiency is 1,360, which corresponds on the chart 



^ Livingston, B. S., and Livingston, G. J., Temperature coefficients in 

 plant geography and climatology, Bot. Gaz. (1913), 56, 349. 



