387 
Dioxide Absorption of Coco-nut Leaves . 
during test series 5 by the pinnae of leaf No. 3, on May 25, i. e. 526 mg. 
The two leaves were of about the same age, each being third from the 
youngest. The character of the day was different in the two cases, however, 
for it was bright all day on May 25, but was dull during the afternoon on 
May 29. The test of the detached pinnae showed clearly that the total 
Diagram 8. Amounts of carbon dioxide absorbed by a detached abaca leaf on May 18, 1918. 
250 
£•30 6-30 8-30 10-30 12-30 RM. 2-30 4-30 6-30 
Diagram 9. Amounts of carbon dioxide absorbed by an abaca leaf on May 31, 1918s 
amount of assimilation was not seriously reduced by detaching the leaf. 
But the diurnal march of carbon dioxide absorption was very different in 
the detached pinnae from any of the pinnae attached to the plant, as is 
shown by Diagram 7. The graph of carbon dioxide absorption in this case is 
more irregular than those of Diagrams % to 6, and shows a very definite maxi- 
mum at the 10.30 a. m. to 12.30 p.m. period, instead of two maxima with an 
intervening depression as was shown by most of the other leaves tested. 
