132 



ZHSSOJVS WITS PLANTS 



parts are most essential to it. A flower is obvi- 

 ously a more complex structure than a leaf. 



140. A week or two later the flower has gone, 

 and a structure like that in Fig. 132 has ap- 

 peared in its place. We know that in the center 

 of this structure are the seeds. We know, also, that 

 the three green leaves will soon perish, as the 

 other parts have perished, and only 

 the little plants which spring from 

 the seeds will bear testimony that 

 there has been a flower. In other 

 words, the purpose of a flower is 

 to produce seeds, by which the 

 plant is perpetuated. 



141. If the above conclusion is 

 true, it follows that the most es- 

 sential or necessary parts of the 

 flower are those which are directly 

 concerned in the production of seeds. These parts, 

 in the hepatica at least, are the very central 

 organs. It is evident, therefore, that if we are 

 properly to understand the flower, we must begin 

 at the center, not at the outside. 



142. A flower of the common mustard is shown 

 in Fig. 133. Secure a flower, and count the parts. 

 The details (less half of the enveloping leaf-like 

 parts) are displayed in Fig. 134. The central 

 part, 0, is to make the seed-pod. The minia- 



Fio. 132. 



After the flower is 

 gone. 



