1911.] New Method of Estimating the Aperture of Stomata. 151 



But in the smaller curve (fig. 8), constructed from -^/E (the square root of 

 the rate of flow), the rise in the curve is from 7 to 12'5, i.e., as 1 : l - 8. This, 

 as far as it goes, confirms our view that .^/E represents the amount of 

 transpiration more closely than does E (the rate of air-flow). 





1 























I— 











V- 

















/ 













j 













S 







5 



2 







Fig. 8. — Experiment 41. Cutting the leaf-stalk of Nicotiana glauca. The small curve 

 constructed from the square root is drawn to twice the scale used for the larger 

 curve. 



