CHAPTER III. 
THE FERTILISATION OF FLOWERS. 
IT is popularly held that the chief end of plants is to 
minister to man’s sense of the beautiful in form and 
colour, but the recent investigations of scientific men 
should dissipate so presumptuous a theory. Man cer- 
tainly does—unless his nature be very depraved— 
derive very great pleasure from the presence of 
flowers; but ¢#e purpose of the fine odours, the 
varied tints and exquisite forms of flowers is that 
the species shall be continued 
by the production of healthy 
seeds. How they are instru- 
mental in effecting this we will 
explain. 
A flower usually consists 
of four series of organs, dif- 
fering widely in form and 
office, but all modifications 
of the simple leaf. These 
are the calyx, consisting of 
leaves called sefals ; the 
corolla formed of leaves called 
petals; the stamens, and the pistil. The calyx and 
the corolla are known as the floral envelopes; the 
Cc 
Fic. 37. 
