BY E. BREAKWELL. 387 



termed by Warming hinge-cells, and known in American liter- 

 ature as bulliform cells, are not fan-shaped, hut in rows ranging 

 in series from 5 to 8, and situated between the primary bundles. 

 Stomata are found on both surfaces of the leaf, the proportion 

 on the lower surface to that on the upper surface being approxi- 

 mately as 3 : 1. They appear on the upper surface at the edges 

 of the series of bulliform cells, and also occasionally about the 

 centre of the series. 



Andropogon affinis R.Br. (Plate xxix., fig. 2). 



In the widest portion of the leaf, there are eight primary 

 bundles, forty-four secondary bundles, and three intermediate 

 bundles. 



In the midrib proper, there is only one primary bundle. On 

 each edge of the midrib, there is also a primary bundle, 

 and that of the midrib is not as large as the others. The 

 chlorophyll-bearing cells of the midprimary bundle are irregular 

 in size, and smaller than those of the other bundles. As in A. 

 inter medius, they are not continued right round the bundle, but 

 are interrupted, on both the superior and inferior surfaces, by 

 sclerenchyma. The chlorophyll-bearing cells of the secondary 

 bundles are much larger than those of the primary bundles, and 

 the mesophyll-sheath is very distinct, 'i'he sclerenchyma on the 

 inferior surface of the primary bundle is not as well developed 

 as in A. hitermedius, nor is that on the superior surface. The 

 sclerenchyma on the superior surface of the primary bundles at 

 the edge of the midrib is better developed than in any of the 

 other primary bundles, and is in direct contact with the bundles. 

 Generally speaking, there is not the same development of scler- 

 enchyma right throughout the leaf as in A. intermedins. 



The epidermal cells on the inferior surface are irregular in 

 size, and are protected by a thin cuticle, which, however, is not 

 nearly so well developed as that of A. intermedins. The epider- 

 mal cells on the superior surface are bulliform in character, with 

 the exception of those over the primary bundles. They penetrate 

 the mesophyll-tissue more than do those of A. intej^medins, are 

 distinctly fan-shaped in character, and arranged in series of 5 to 



