Flowers 



The sepals are sometimes; surely, only protective 

 bracts which have been further modified. Either sepals 

 or petals and sometimes both of them become abortive. 

 Occasionally petals become stamens, which may mean 

 that in those cases they were at first modified stamens.^ 



In a sense one might say that flowering is the end 

 towards which every effort of the plant is directed. 

 Quite a number of the Monocotyledons die as soon as 

 they have flowered. Young trees which are unhealthy 

 and miserable-looking often produce great quantities of 

 flowers and fruits and at a very precocious age, long 

 before their normal and vigorous contemporaries show 

 the slightest desire to flower. One might suppose that 

 such miserable seven- or eight-year-old trees had a 

 foreboding of death and wished to do what they could 

 to perpetuate the species. One sees the same hurried 

 flowering also when cut off leaves of Torenia are in- 

 duced to take root. The ugly little stems so formed 

 flower when only an inch or two in height. 



But such facts do not necessarily bear out any such 

 explanation. 



In a flower, the life that is going on differs in many 

 ways from the ordinary proceedings in other parts of 

 a plant's body. There is a very active formation and 

 storing up of rich proteids, sugars, hard stony substances, 

 colouring materials, strong perfumes and the like, which 

 may not be required anywhere else except in the flowers. 

 So it is not surprising to find that the temperature in 

 an opening flower is often distinctly higher than that 

 of the surrounding air. So also the respiration in 



lobed leaflet carrying a female sporangium. Bower thinks that all green leaves 

 were at one time spore-leaves and only intended to bear a sporangium. 

 Gradually more and more of their cells became sterile and ceased to produce 

 spores, but this refers to the time when the plants were primitive ferns and 

 long before flowers appeared. 



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