66 BOTANY. 



plant-body; but in the higher groups they become dis- 

 tinctly set off, and are eventually difEerentiated into a mul- 

 titude of structural and functional forms. 



114. Every plant in its earliest (embryonic) stages is 

 simple and memberless ; and every member of any of i^e 

 higher plants is at first indistinguishable from the rest of 

 the plant-body ; it is only in the later grovs'th of any mem- 

 ber' that it becomes distinct ; in other words, every member 

 is a modification of, and development from, the general 

 plant-body. 



115. Likewise, where equivalent members have a differ- 

 ent particular form or function, it is only in the later 

 stages of growth that the differences appear. All equiv- 

 alent members are alike in their earlier stages, whether, 

 for example, they eventually become broad green surfaces 

 (foliage-leaves), bracts, scales, floral envelopes, or the essen- 

 tial organs of the flower. 



116. Generalized Forms. — These facts make it necessary 

 to have some general terms for the parts of the plant-body 

 which are applicable to them in all their forms. We must 

 have, for example, a term so generalized as to include 

 foliage-leaves, bracts, scales, floral envelopes, and all the 

 other forms of the so-called leaf-series. So, too, there is 

 need of a term to include stems, bulb-, bud- and flower- 

 axes, root-stocks, corms, tubers, and the other forms of the 

 so-called stem-series. 



117. By a careful study of the members of the higher 

 plants we find that they may be reduced to four general 

 forms, viz., (1) Oaulome, which includes the stem and the 

 many other members which are found to be its equivalent; 

 (3) Pliyllome, including the leaf and its equivalents; (3) 

 the Boot, which includes, besides ordinary subterranean 



