42 THE STORY OF PLANT LIFE 



also, like the visits of insects, etc., more readily ob- 

 served by the beginner, and therefore useful factors 

 in arousing that interest and sustained observation, 

 and the asking of questions as to the why and the 

 wherefore of such phenomena, which is so necessary 

 before entering upon the more serious phase of 

 study. 



The colour of flowers in general is an interesting 

 subject, and is in the main connected with pollina- 

 tion. The colours are due to pigments in the cells, 

 akin to those of the leaves, etc. 



There are a few main types of colour which dis- 

 tinguish flowers, yellowish-green, yellow, red, white, 

 blue. Red, yellow, blue or white are the commonest. 



In addition to the colour of the flower there are the 

 markings, such as spots. There are also lines, fre- 

 quently converging to the base of the corolla, which 

 are honey-guides to direct the insect, in entomophilous 

 flowers, to the honey. White is the predominant 

 colour in flowers that bloom at night, and in aquatic 

 floating plants, as being the most conspicuous against 

 the dark background of the water in the last case. 



Some flowers are versicolorous and turn colour. 

 Some last long, some are fugaceous, or soon drop. 

 In others the flowers soon fade. The time of flower- 

 ing is an interesting phenomenon, and so is the 

 duration of each flower. Both these are features that 

 are connected with the season, the temperature, the 

 soil, and the needs of the plant, or its adaptation in 

 relation to insects. 



