122 



BOTANICAL GAZETTE 



[FEBRUARY 







Alcohol- water soluble fraction (F 2 ). — Table V shows a 



distinctly higher average percentage of these extractives at the 

 higher temperature, although the order of difference is not large. 

 When, however, the composition of this fraction is examined cer- 

 tain striking differences are noted. The high temperature leaves 

 contain a much lower percentage of both total and reducing sugars 

 (table VI) and a lower percentage of polysaccharides (table VII). 

 The high temperature leaves contain about twice as much nitrogen 



(as determined by the unmodified 

 Arnold- Gunning process) as do the 

 low temperature leaves (table IX). 

 In other words, the amount of active 

 metabolic rtitrogen, such as amino 

 acids, polypeptides, and simpler water 

 soluble proteins, is much higher at 

 the higher temperature. The amount 

 of nitric N is also higher at the higher 

 temperature, as was indicated when 

 the modified Arnold- Gunning process 

 was used. The results of the nitric 

 N determinations are not reDorted in 



this 



paper. The high temperature 



Fig. i 6. — Influence of tem- 

 perature on maturation (photo- 



contain near 



percentage of alcohol-water soluble 

 graphed May 16): no. 12, phosphorus. Duplicate determina- 

 tions on one set of samples (nos. 24 

 and 87) indicated that this difference 



norma 



fertilization (warm 

 normal 



zation (cool house) ♦ 



was very largely due to the much 

 higher percentage of inorganic phosphorus at the higher tempera- 

 ture. These results are appended, although it is recognized that 



more data are needed before anv swppnina apnpralizatirmQ ran be 



made, 

 nation. 



The Powick-Chapin method was used in this determi- 



TotalP 



Inorganic P 



No. 24 

 No. 87 



Percentage of 

 fraction 



0.82II 



o . 5096 



Percentage* of 

 entire leaf 



O.2770 

 O.I417 



Percentage of 

 fraction 



O.6240 

 O.2567 



Percentage of 

 entire leaf 



0.2I05 

 O.0714 



t 



