308 THE EDUCATIONAL CLAIMS OF BOTANY. 



other parts of the plant. Its differences from flowers and stems 

 enable the mind readily to differentiate it in idea, while the 

 essential resemblances of leaves of all kinds make their inte- 

 gration into one general conception inevitable. 



Our primary scholar, then, starting at the level of ordinary 

 perception, is to increase his discriminative power. He must 

 learn to discover minuter differences and resemblances, and to 

 make his ideas more definite and precise. To this end he 

 enters upon the exercises of the First Book, and begins a care- 

 ful inspection of leaves. He soon finds that they vary consid- 

 erably ; that their most conspicuous feature that which he 

 has hitherto regarded as the entire leaf forms, in most cases, 

 but one part of the leaf. Having gained a clear idea of this 

 part, he marks his conception of it by a sign which he finds to 

 be the word Hade. Another part, almost always present, he 

 distinguishes as the leaf-stem, and names it the petiole ; and 

 still another part, probably never before noticed, he learns to 

 recognize as the stipules. 



He thus begins with the recognition of simple differences, 

 the idea of the leaf being resolved into three component ideas. 

 But each of these component ideas is crude from lack of obser- 

 vation of the varying forms of different blades, petioles, and 

 stipules. Observation is now extended to new specimens, and 

 as it goes forward new differences are perceived among these 

 parts. The blade turns out to be composed of different ele- 

 ments. Its framework is differentiated from its soft, pulpy 

 covering, receives its name, and then this part opens a new 

 field of observation in recognizing and comparing the different 

 modes and variations of the venation, as it is called. % 



Having gone over simple and compound leaves, he next 

 passes to the examination of the stem. Here, also, his first 

 notion is simple and indefinite, but, when a good many have 

 been noticed, marked differences of appearance present them- 

 selves, and stems begin to fall into groups, which he describes 

 as round, square, erect, trailing, creeping, etc., as the case may 

 be ; while closer observation reveals still minuter characters of 

 difference and resemblance among them. Inflorescence, flow- 

 ers, and roots, are successively studied in the same manner. 



