76 AEEANGEMKNT OF FLOWERS ON THE STEM. [lESSON ll". 



by the midrib so that the two halves are placed face to face, it is 

 condupUcate (Fig. 149), as in the Magnolia, the Cherry, and the 

 Oak : when folded back and forth like the plaits of a fan, it is plicate 

 or plaited (Fig. 150), as in'^the Maple and Currant. If rolled, 

 it may be so either from the tip downwards, as in Ferns and the 

 Sundew (Fig. 154), when in unrolling it resembles the head of a 

 crosier, and is said to be circinate ; or it may be rolled up parallel 

 with the axis, either from one edge into a coil, when it is convolute 

 (Fig. 151), as in the Apricot and Plum, or rolled from both edges 

 towards the midrib ; — sometimes inwards, when it is involute (Fig. 

 152), as in the Violet and "Water-Lily ; sometimes outwards, when 

 it is revolvie (Fig. 153), in the Eosemary and Azalea. The figures 

 are diagrams, representing sections through the leaf, in the way 

 they were represented by Linnaeus. 



LESSON XL 



KESCENCE. 



195. Thus far we have been considering the vegetation of the 

 plant, and studying those parts, viz. root, stem, and leaves, by which 

 it increases in size and extent, and serves the purpose of its indi- 

 vidual life. But after a time each plant produces a different set of 

 organs, -^ viz. flowers, fruit, and seed, — subservient to a different 

 purpose, that is, the increase in numbers, or the continuance of the 



