BOTANY. 



or consists of two little leaf-like appendages, called stip- 

 ules, shown in Fig. 3, s s, and still smaller in Fig. i. 



When the petiole is 

 absent, the leaf is said 

 to be sessile ; and if stip- 

 ules are wanting, it is 

 described as exstipulate. 

 Fig. i represents a petio- 

 late- stipulate leaf that 

 is, a fully-developed or 

 complete leaf. 



When, as in Fig. 4, 



the sheath-like leaf-stem, g, ends above, at the 

 base of the blade, /, in a little membranous 

 appendage, lig., we call this body a ligule. It 

 is a very common sort of stipule. 



Gather leaves of all kinds, from the grass 

 and herbs underfoot, from bushes, shrubs, and 

 trees, and find and name the parts that compose each one 

 of them. Say whether they are sessile or petiolate, and 

 whether they are stipulate or exstipulate. 



FIG. 3. 



FIG. 4. 



EXERCISE II. 

 Venation. 



The lines, fine and coarse, that are seen running 

 through the blades of leaves, are called veins j and the 

 various ways in which they are distributed are spoken of 

 generally as the venation of the leaf. 



When there is but one large central vein, reaching 

 from the base to the apex of the blade, and giving off 

 branches from its sides, it is called a midrib (Fig. i). 



When there are several large veins which thus cross 

 the blade, as seen in Figs. 5 and 6, they are called simply 

 ribs. Branches from the rifes are known in botanical de- 

 scription as veins, and the smallest of these lines which 



