17° 



BOTANICAL GAZETTE 



[FEBRUARY 



Etiolated Vicia Faba seedlings were used for the later work. 

 For the moisture and titration acidity determinations the plants 

 were grown in moist sphagnum in pans. When the shoots had 

 reached a suitable length (6-8 cm.) they were exposed to gravity by 

 setting the pans on edge. In collecting the material, the leaf was 

 removed and the stem divided as accurately as possible into upper 

 and lower flanks. The terminal 3-4 cm. were used. For the other 

 work the plants were grown in moist sawdust in a dark cool room. 



TABLE I 



- 



Moisture and acidity in corn nodes exposed to gravity 



Time of 

 exposure 



Moisture 



Hours 



3 



3 



6 



6 



9 



9 



12 



12 



15 



18 



18 



21 



21 



24 



24 



27 



27 



Upper flank 

 (percentage) 



86.68 

 87.00 



86.85 

 87.09 



8497 

 84.04 



83.80 



.83.10 



85 5o 

 84. 24 



83 So 

 82.39 



82.35 

 82.31 



83 -73 

 82.97 

 81.39 



81.44 



Lower flank 

 (percentage) 





87.IO 



86.83 

 86.98 



87.18 



84-43 

 85.IO 



83.19 



82.72 



84.61 



84.26 



83-7I 

 82.79 



83.40 



82.71 



82,99 



82.90 



82.19 



82.44 



Difference 

 (percentage) 



+O.42 



— O.17 

 +O.13 

 +O.09 

 -O.54 

 + I.06 



— O.61 

 -O.38 

 -O.89 

 +0.02 

 +0.2I 

 +O.40 

 + I.05 

 +O.40 

 -O.74 



— O.07 

 +O.80 

 + I.OO 



Acidity in cc. 0.05 N NaOH 



PER GM. FRESH WEIGHT 



Upper flank 



O.49 

 O.47 



O.47 



O.51 

 O.46 



O.51 

 O.49 



0-57 

 O.47 



O.47 



O.38 



O.51 

 O.61 



O.67 



0-55 

 O.58 

 O.64 



O.65 



Lower flank 



O.48 

 O.47 



0-53 



0-59 

 O.48 



0.54 

 O.50 



059 

 O.46 



0.54 

 O.48 



0.5S 

 O.65 



O.70 



0.57 

 O.65 



0.57 

 O.76 



D iff erence 



O.OI 



+O.06 

 +O.08 

 +0.02 

 +O.03 

 +O.OI 

 +0.02 



— O.OI 



+0.07 



+O.IO 



+0.04 



+0.04 

 +0.03 



+0.02 



+0.07 



—0.07 



+0.11 



When 



they 



The 



boards were placed upright in a large galvanized iron container, 

 under a spray. They were kept in this position for at least 24 hours, 

 and then exposed to gravity by rotating the board through 90 . 



determination of moisture the 



dried 



to constant weight in vacuo at 8o° C. The samples varied in 

 weight from 2 to 5 gm., according to the number and size of the 



nodes used. 



Table I gives the results of the series in which the 



