AGRELIUS: FOOD-CONDUCTION IN PLANTS. 



177 



TABLE II. 



Pinus laricio Bort 



Yucca g-lauca Nutt 



Salix alba, var. vitellina (L.) Koch 



Populus alba L 



Populus deltoides Marsh, (stem) 



Populus deltoides Marsh, (root) 



Menispermum canadense L 



Rubus occidentalis L 



Gymnocladus dioica (L.) Koch 



Celastrus scandens L 



Psedera quinquefolia (L.) Greene 



Vitis aestivalis Mx 



Abutilon theophrasti Medic 



Symphoricarpos orbiculatus Moench 



Average for the above plants with pitted 

 walls 



Average from plants where pits were not 

 observed 



Difference (+) or (— ) 



Thickness in microns of walls between— 



S. t. and 



s. t. 



0.65 

 0.58 

 0.40 

 1.08 

 0.50 

 1.39 

 0.45 

 0.45 

 0.40 

 0.50 

 0.70 

 2.3S 

 0.65 

 0.60 



0.763 

 0.549 



S. t. and 

 comp. 

 cells. 



C.40 

 0.35 

 0.53 

 0.35 

 1.00 

 0.40 

 0.45 

 0.30 

 0.38 

 0.50 

 1.72 

 0.45 

 0.40 



0.556 

 0.394 



S. t. and 

 m. ray. 



+0.214 +0.162 



0.35 



0.45 



0.50 



0.50 



4.17? 



0.80 



0.50 



0.941 

 0.633 



+0.308 



Tracheal 

 tissues 



and 

 xyl. par. 



2 58 

 1.78 

 1.85 

 2.73 

 2 80 

 4.88 

 2.48 

 2.19 

 3.94 

 3.08 

 2.20 

 3.83 

 a. 25 

 2.78 



2.884 

 2.922 



-0.038 



Tra- 

 cheal 



tissues 



and 

 m. ray. 



1.60 



1.28 

 1.65 

 1.85 

 3.24 



1.75 

 3.16 

 1.85 

 1.85 

 1.77 



1.92 



1.993 

 2.133 



—0.140 



