Professor Marshall Ward, On the Question of 
Table IV. 
Facsimile of a plotting and direct counting of stomata, hairs, 
ribs, &c., on an area of squared paper representing a little more 
than one square mm. of leaf surface. 
B. canadensis. Upper surface. 
Stojivyh Oj /fO , HoaAo (2. 
Explanation of diagram. The vertical lines are a, the margin ; b to e, ribs with 
distances between. The dots represent the stomata and the crosses the hairs, each 
in its proper relative position. A square of glass representing exactly 1 sq. mm. 
was then placed in 5 positions on this area, and the average count taken. 
