NUMBER OF STOMATA 53 
In one square 
millimeter 
Upper Lower 
side side 
Olive, Olea europaea..............e eee 0 625 
Black Walnut, Juglans nigra.......:..... 0 461 
Red Clover, Trifolium pratense........... 207 335 
Lilac, Syringa vulgaris................... 0 330 
Sunflower, Helianthus annuus........... 175 325 
Cabbage, Brassica oleracea............... 138 302 
Sycamore, Platanus occidentalis..:....... 0 278 
Lombardy Poplar, Populus nigra italica. . . 55 270 
Hop, Humulus lupulus.................. 0 256 
Plum, Prunus domestica................. 0 253 
Apple, Malus malus..................... 0 246 
Barberry, Berberis vulgaris.............. 0 229 
POR, SUI BAIVUIN 5 5 <4 os ai vade ander 101 216 
Box, Buxus sempervirens................ 0 208 
Cherry, Prunus mahaleb................. 0 204 
Thorn Apple, Datura stramonium........ 114 189 
Indian Corn, Zea mays.................. 94 158 
Cottonwood, Populus deltoides........... 89 131 
Wind Flower, Anemone nemorosa........ 0 67 
Lily, Lilium bulbiferum.................. 0 62 
Epis (Tets -MOrManiCds <6. 2622. isid neds 65 58 
Oats. Avena sativa........... ccc ee eee eee 48 27 
House leek, Sempervivum tectorum....... 11 14 
Water Lily, Castalia lotos................ 625 0 
relation to the substomatal chambers and the inter-cellular 
spaces of the leaves. 
(d) Make a cross-section of the leaf of oleander (Neriwm 
oleander) or rubber plant (Ficus elastica). In the former the 
epidermis is in two layers, and in the latter sometimes as much 
as four. This point can only be determined by making com- 
parative sections of very young leaves and old leaves. Note 
the depressed, cistern-like pits in the oleander leaf, into 
which the stomata open. 
