Ewart and Rees .— Transpiration and the Ascent of 
The Resistance to Flow under Varying Pressures. 
The resistance to flow naturally depends upon a variety of factors, and 
from the data already given as to the dimensions of the vessels, it is 
Mead inCms. 
Rate of floo under oarying heads in non-saturated-yi, and in saturated br&nch*E>. 
Figured. Eucalyptus viminall's. 
evident that, other things being equal, it will be more rapid in large 
branches and main stems than in equal lengths of the smaller branches 
under similar heads. In the following experiments the branches for each 
