THE LEAF. 45 



EXERCISE XIII. 

 Petioles, Surfaces, and Colors. 



THE following schedule has three new questions 

 added to it. The first is Petiole ? The shape of the 

 petiole, whether round, roundish, or half-round, should 

 be observed, and written down. And if it be re- 

 markable for its length or shortness, if it be unusu- 

 ally limber, or unusually stiff, you must mention 

 these peculiarities about it. 



COLOR ? To this question the answer is easy. 

 Leaves are sometimes light green, sometimes dark 

 green ; and sometimes the upper surface is one color, 

 and the lower another. There are spotted and striped 

 leaves, and some leaves have a brownish or reddish 

 tinge. All these things are to be noted when you 

 see them. 



SURFACE ? Observe whether the surface of a leaf 

 has hairs or not. If it has hairs, write hairy after 

 this question ; but, if it has no hairs, write glabrous, 

 which means free from hairs. 



Again, surfaces are either smooth or rough, ob- 

 serve which, and write the result in the schedule. 



Some leaves have a very shiny surface, and some 

 are very dull, and these differences should be ob- 

 served, and ^vritten down ; but these qualities need 

 not be noted unless they are strongly marked. 



These characters cannot be conveniently repre- 

 sented by pictures, but they are readily seen in 

 actual leaves. Feeling sure that you can easily make 

 them out, we have not attempted to describe a leaf 

 in schedule eight. 



