PHYTOGENY. 225 



1134. In the division of the ribs of the leaf the in- 

 ternal arrangement of the woody fasciculi in the stem 

 has been placed before our eyes, as by the scalpel of an 

 anatomist. 



1135. From the arrangement of the ribs of the leaf 

 the structure of the whole plant can be recognized and 

 its character determined. The leaf is the table of con- 

 tents or index of the stem. 



1136. Plants, which have no trachea, have also no 

 leaf-ribs Mosses. 



1137. Plants, which have only isolated or non- 

 ramifying fascicles of trachea?, have parallel leaf-ribs that 

 do not ramify Monocotyledons. 



1138. Plants, which have a circle of trachea?, or rings 

 of wood, have leaves with ramified ribs reticular leaves 

 or true foliage Dicotyledons. 



1139. The stronger indeed the ramification of the 

 leaf-ribs, by so much the higher is the perfection of the 

 leaf. The lowest leaf is that devoid of ribs, the higher 

 that with parallel ribs, the highest being the reticular- 

 veined leaf. 



1140. The number and forms of the leaves that pro- 

 ceed from a bud, depend partly upon the number of 

 tracheal fascicles, which pass out of the ramule into the 

 leaf, partly upon the form of the leaf-bud. 



1141. If the bud be simply ruptured at its apex or 

 only between two fascicles of trachea?, there then origi- 

 nates the spathiform leaf. 



1142. If the cellular substance between several tra- 

 cheal fascicles be consumed by the severing action of 

 light and by the air, then the bud divides into several 

 leaves. 



1143. The fundamental form of the leaf is the ovi- 

 form, because the bud is to be thought of as being round. 

 Through the elongation or compression of the bud, lanci- 

 form,cordiform leaves, &c. originate. Besides it appears, that 

 the leaf-buds, at least those of the reticular-veined leaves, 

 burst in a circinate manner, like the ferns, and unroll 

 themselves. Therefore the leaves are unilateral and 



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