/l/ Refers to the ratio of the volume of COg released to the volume of O2 absorbed. 

 /2/ Young leaf at 25° C, I65-295. /3/ Young leaf, 1,133- /V Data applicable to 

 young leaf. /5/ Recorded values represent data from two different tests; there- 

 fore, a respiratory quotient is not calculated. /6/ At 20° C, 125 cu mm COo re- 

 leased. /7/ At 0° C, 1.5; at k.f C, 17.2; at 15-5° C, 51. /8/ At 25° C, 3l8; at 

 26° C, 353; at 29° C, 37'*. /9/ Value applicable to winter leaves. For young sum- 

 mer leaves, 56. /lO/ Data applicable to leafy stem. 



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