14 



observer), it is quite a simple matter to determine to 

 which category the veins belong. In ryegrass, the 

 veins (except a few here and there) are dimly visible, 

 whereas in fescue almost all stand out as sharply 

 defined and pure white lines. This method of exam- 

 ination by transmitted light often reveals characters by 

 which grasses, externally very similar, may, at once, 

 be distinguished. The student ought to examine the 

 blades of all the grasses in this way. 



Perennial Ryegrass. 



xiv. 7 . The blade is rounded off at the base, and, usually, 

 has a pair of acute ear-like processes. This is called 

 an eared leaf base. The lower surface is always 

 strongly shining. 



xiv. 6. The margins of the blade usually run parallel 

 till past the middle, when they begin to converge, 

 ultimately forming a tapered, somewhat acute point. 



xiv. 9. The ribs on the upper surface are prominent and 

 rounded. The keel, that is the mid rib on the lower 

 surface, is also prominent. 



The ligule a collar-like outgrowth at the junction 

 of sheath and blade is remarkably short and in- 

 conspicuous. 



xiv. s. The sheath is flat. Sheath flatness depends upon 

 the arrangement of the contained leaf blades. If the 

 blades are closely folded over one another, as is the 

 case in this ryegrass, then the sheath is flat. 



Italian Ryegrass. 



XL 5, 6. This resembles the preceding in almost every leaf 

 detail. The blades are, however, rolled, and the 

 sheath accordingly round. 



