IOWA ACADEMY OP SCIENCES. 
135 
The mestome portion is compact. The larger secondary 
mestome bundlts occur in sets of three on either side of the 
carene. The bundles number twenty-four and twenty -eight on 
either side of carene. The mestome portion extends nearly to 
the edge of the leaf, where stereome occurs. The edges of the 
leaf are rounded. 
The stereome portion is quite generally distributed and varies 
not essentially from this portion in other species. The sec- 
ondary mestome (M.) bundles are not characteristic. 
ANDROPOGON SORGHUM. 
(PL xiii, Fig. 7; PL xiv, Fig. 10.) 
Cuticle (C.) and epidermal cells (E. C.) are not characteristic. 
Bulliform cells (B. C. ) vary in number from two to eight. Their 
size is somewhat variable. These cells merge so gradually into 
the smaller ones which are usually found above the mestome 
bundles that it is difficult to distinguish them from the epider- 
mal cells on this side of the leaf. The four types of bundles 
common in other species studied occur also in this species. 
The carene is distinguished from that of other species studied 
in that the chlorophyll-bearing parenchyma cells (C. B. P.) are 
small, not so regular, and do not contain as much chlorophyll 
as in other species studied. The intercellular space adjoining 
the ringed duct is large. The stereome (Ste.) above and below 
carene bundles is conspicuous. Epidermal cells directly below 
carene are rectangular in shape. The mestome (M.) bundles 
are not characteristic in this species. The rectangular chloro- 
phyll-bearing parenchyma cells surround the bundles. The 
mestome bundles are numerous and occupy the same relative 
position as in other species studied. Edges of leaf have a well- 
developed stereome. The number of cells varies. The meso- 
phyll (Mes.) is not so dense as in other species. The shape and 
size of the cells varies considerably. The uncolored parenchyma 
cells occur above and to sides of upper half of carene. These 
cells are unusually large, and occupy a large portion of the 
mid-rib. They gradually become smaller toward the edges of 
the leaf. Stereome above parenchyma occurs in from two to 
three rows. The contents of bundles are not essentially dif- 
ferent from others already studied. The breadth of the leaf as 
well as the large mid rib is sufficient to characterize it. 
