1917] 



DENN Y—PERMEA BILI T Y 



387 





osmometer. The latter was then placed again in the 



made 



IX 



more permeable 



The peanut membrane 



other, and the favorable direction is from the outside toward the 



inside. 



TABLE IX 



Rate as affected by direction of flow of water through membrane 



of Arachis hypogaea 



Number 



1 



2 



3 



4 



5 

 6 



7 

 8 



9 

 10 



11 



12 



13 



14 



Diameter 



of HOLE 



OsMo-rrc 



PRESSURE 



Water (in mg.) passing through membrane per hour 



In 



Out 



8 mm 



u 



u 



a 



a 



u 

 tt 

 u 

 u 

 u 

 u 



u 

 a 



tt 



5 



67 



u 

 u 



IOO 



u 



25 



48 



tt 

 tt 



139-52 



137. 54 

 124. 26 



9925 

 396.21 



236.88 



164.38 

 36.89 



30 55 



In 





Out 



95 

 87 



93 



43 



207 



158 

 121 



20 



27 

 70 



79 



35 

 44 



49 



92 

 20 

 09 

 21 



94 



27 

 82 

 70 



17 



87 



65 



75 

 06 



Percentage 



decrease 



from in 



to out 



135 l6 

 III. 18 



98.86 

 402.67 

 224.80 

 202.32 



30.04 

 38.02 



106. II 

 III. 82 



53-77 

 63.69 



71.88 



90.91 

 84.58 



205.97 

 146. 12 



127 59 



2470 

 26.98 



44 -5o 



32 



3i 



25 

 56 



49 



34 

 32 



32 

 20 



33 

 38 



33 

 29 



3i 



. "In" means direction outside of seed toward inside; "out" means direction inside of seed toward 

 outside. 



Measurements with the seed coats of Prunus Amygdalus 

 dulcis gave the following results: 



Rate in 

 Rate out 

 Rate in 



48 . s mg. per hour 

 42.6 " u u 



48.5 * " U 



Rate out = 40 . 4 



a 



a 



u 



Measurements made 





coat of Dioon edule did not indicate any observable difference in the 

 rate of penetration in opposite directions. This difference in the 



differenc 



types of membranes 



posed of two or more 



The peanut and almond seed coats 



different physical and chemical nature on opposite sides; such is 



