BUDS AKD LEAVES. 



31 



caducous; others remain until autumn, and are called 

 deciduous ; others live through the winter, and are called 

 persistent, or evergreen. 



72. I have told you that a leaf consists of a petiole and 

 lamina ; that the lamina is composed of cellular tissue and 

 the cuticle ; that the midrib is but a continuation of the 

 "woodj fiber of the petiole, and that the branches that 

 spring from it are primary veins, and they again are sub- 

 divided into secondary and veinlets. You have heard that 

 the minute pores on the under surface are mouths by which 

 the plant performs the operation of breathing and feeding. 

 You have been taught how to distinguish between seminal, 

 primordial, and characteristic leaves, and the situation of 

 cauline, radical, and sessile leaves. We will now look at 

 some pictures of the various leaves, and learn their names. 



73. Leaves are divided into simple and compound. Sim- 

 ple have but one blade, as the violet, cottonwood, crape 

 myrtle. Here are pictures of some of the various forms 

 of simple leaves : 



Fig. 17. 



Ovate, 



(Quince.) 



Fig. 18. 



Elliptical, 



(Black Haw.) 



Fig. 19. 

 Lancoleate, 

 (Flowering Almond.) 



72, Repeat all that you have now learned concerning the leaf. 



73. The teacher should make the pupil not only describe each leaf, but identify 

 each by specimens, and also draw thera on the blackboard. 



