138 



FOUNDATIONS OF BOTANY 



(in palmately veined leaves) or to the midrib (in pinnately 

 veined ones). Such divided leaves are shown in Figs. 

 96 and 97. 



In still other leaves, known as compound leaves, the 

 petiole, as shown in Fig. 102 (palmately compound), or the 

 midrib, as shown in Fig. 103 (pin- 

 nately compound), bears what look to 

 be separate leaves. These differ in 

 their nature and 

 mode of origin 

 from the portions 

 of the blade of a 

 divided leaf. One 

 result of this dif- 

 ference appears in 

 the fact that some 

 time before the 

 whole leaf is ready 

 to fall from the 

 tree or other plant 

 in autumn, the 

 separate portions 

 or leaflets of a 

 compound leaf are 

 seen to be jointed- 

 at their attach- 

 ments, just as whole leaves are to the part of the stem from 

 which they grow. In Fig. 102 the horse-chestnut leaf is 

 shown at the time of falling, with some of the leaflets 

 already disjointed. 



That a compound leaf, in spite of the joints of the 



FlG. 103. Pinnately Com- 

 pound Leaf of Locust, 

 with Spines for Stipules. 



FIG. 104. Pinnately 

 Compound Leaf of 

 Pea. A tendril takes 

 the place of a terminal 

 leaflet. 



