AT THE PERIOD OF PUBERTY. 161 



Cherry and Garden Rose; although, as a general rule, 

 when once the development of the axis has reached its 

 limit in flowers, there is no recurrence again of the vege- 

 tative period. 



And here it is necessary to appreciate fully the relative 

 physiological rank or importance of the floral organs. To 

 understand this, we must study not only the subordina- 

 tion of function which subsists amongst the floral organs, 

 but also their presence or absence in the greater number 

 of flowers ; for it may be very safely concluded that those 

 floral organs which are present the most frequently in 

 flowers, and the last to disappear, are in reality the most 

 necessary to the exercise of the reproductive function. 



The popular idea of a flower is usually associated with 

 something showy and colored, and hence the flowers of 

 the Judas Tree {Cercis Canadensis), the Dogwood [Oornus 

 Florida), and the Tulip Ti-ee [Liriodendron tulipifera), are 

 easily recognized ; but not the flowers of the Larch, Cedar, 

 or Pine. The flowers of these trees take a lower form of 

 development, and require the searching eye of the ITatu- 

 ralist to detect them. Such humble forms of floral struc- 

 ture are, in reality, the most attractive and interesting to 

 the philosophical Botanist. He can admire the rich colors 

 of a Camelia or Geranium, -but there is something quite 

 as pleasing when he recognizes simplicity of structure, 

 where calyx and corolla have disappeared, and nothing 

 remains but the stamens and pistils, the parts absolutely 

 necessary to reproduction. These are the most highly 

 metamoi-phosed of the leaf-organs of the plant, to which 

 all the others are simply accessory. Propagation cannot 

 be effected -vfithout them, hence they are the very last to 

 disappear from the organism, in descending from the higher 

 to the lower orders of the l^hanerogamia or flowering 

 plants ; and wherever they are present, there is a true 

 flower. Stamens and pistils may be distinctly seen, at 

 certain seasons of the year, in grasses, sedges, and rushes, 

 which are therefore very properly regarded by Botanists 

 as flowering plants, notwithstanding their sombre appear- 



12 



