332 MACDOUGAL AND SPOEHR— GROWTH AND IMBIBITION. 



Swelling of Joints Formed in igi6. 

 (See Fig. 8.) 



Water. HCl N/ioo. NaOH N/ioo. 



Per Cent. Per Cent. Per Cent. 



May i8, 1916 24.3 30.0 40.0 



June 2, " 23.6 16.4 22.9 



" 13, " 70.1 41-5 49-1 



Aug. 3, " (swelled at Carmel) 16.6 14.0 14.3 



" 3, " (grown and swelled at Carmel) . 18.2 9.3 15.7 



Nov. 2, " 20.5 21.0 22.2 



3, " 146 21.3 19.5 



4, " 28.0 28.0 28.3 



" 5, " 27.9 26.0 24.7 



" 6, " 20.8 18.4 17.1 



" 6, " 27.9 26.0 24.7 



" 23, ^ " 44.0 53.5 46.0 



" 23, " 34.4 34.9 35.3 



" 23, " 49.3 47-9 47-0 



" 23, " 48.0 45.4 35.3 



Jan. 24-25, 1917 (12 sections) 25.7 27.9 25.0 



Feb. 20-21, " (6 " ) 10.7 II. 7 10.8 



Mar. 23-24, " (6 " ) 9.4 12.0 10.9 



April 24 21.8 20.4 13.9 



20.4 21.8 33.8 



sodium hydrate. In.spection of the data obtained by the chemical 

 analyses fails to bring to light any connection between the amount 

 of imbibition and the proportion of any carbohydrate or salt present. 

 The diverging variations suggest combinations of substances to 

 which the swelling may be due. It is to be noted that the propor- 

 tionate swelling of the sections would be lowered by the thickness 

 of the sections which are fifty to seventy times the diameter of the 

 colloid sections used in other experiments. Furthermore, the amount 

 of swelling is in all probability lessened by the presence of mechan- 

 ically resistant fibrovascular tissue. 



Imbibition and Carbohydrate Metabolism. 



In the foregoing pages special attention has been directed to the 

 conditions afifecting imbibition and the water-absorbing capacity of 

 the growing plant cell. It is evident that the metabolic activity of 

 the cell itself afifects imbibition very greatly; an accumulation of the 

 intermediate or end products of respiration may thus cause an in- 



