MOSSES 91 



the leaves of the various plants described; but 

 this particular portion of moss- structure deserves 

 something more than a mere passing notice, for 

 not only is the leaf important in the economy of 

 the plant, but its form and structure generally 

 constitute clues of no little value in the diagnosis 

 of any particular specimen, while it is at all times 

 an object of beauty for microscopic examination. 

 "We have already learned enough, I think, to 

 realise that there is a great diversity, both of size 

 and form, to be met with in moss leaves, a fact 

 that will be still further emphasised by a glance 

 at Plate VII., where more than thirty different 

 leaves are depicted. It is manifestly impossible 

 to refer in detail to every one of these, but a 

 few examples may be taken as illustrating some 

 of their general characteristics. 



In size, moss leaves may vary from the tiny one 

 given at fig. 13 which would appear as nothing 

 more than the merest speck, when seen by the un- 

 assisted eye to the far larger and easily recog- 

 nised one at fig. 22. In form they may be long 

 and narrow (fig. 20), lance-shaped (fig. 11), egg- 

 shaped (fig. 8), spoon-shaped (figs. 16 and 25), 

 etc. ; the apex may be blunt (fig. 8), or tapering 

 (figs. 2 and 10), or ending in a small point 

 (fig. 22), or in a long point (figs. 18, 23, and 31). 

 The edge, too, may be plain (fig. 19), bordered 

 (fig. 22), toothed (figs. 6, 11, 12, and 28), bordered 

 and toothed (fig. 29), wavy (fig. 32), rolled-back, 



