Dixon and Atkins — Osmotic Pressures in Plants. 



55 



Table IV. 

 Acer macrophyllum, April 14th. 



As the chief interest attaches to the values of A - A e , E, and S, they have 

 been recorded in Table V, the figures for the three trees at different levels 

 being placed side by side for the sake of comparison. Graphs of the concen- 

 trations of the non-electrolytes at different levels, and at different dates, are 

 given in the figure on the next page. 



Table V. 

 Acer macrophyllum. 



From Tables II, III, and IV it may be seen that the osmotic pressure 

 of the transpiration stream is greatest at the top of the stem in each 

 case. While this is so the gradient and the absolute value vary greatly 

 at different seasons. In the autumn the root possesses higher osmotic 



