8 A GENERAL VIEW OF PLANTS 
cycle of a plant returns us to the place of starting. The series of 
events may be represented as shown in Figure 1, and in tracing 
them one can begin at any point. The yield of the plant at 
maturity depends upon how well it has done at the different 
stages in its life cycle. The purpose of cultivation is to help the 
plant to do well at all stages, and it is for this reason that we look 
after the fertility of the soil, select seed, prepare a seed bed, sow 
or plant a certain amount of seed and in a certain way, prevent. 
the growth of weeds, etc. But often methods of cultivation 
must take into account the structure and function of plant 
organs as they occur at the different stages in the life cycle of 
the plant, and unless the peculiar features of the plant are 
understood, the methods employed in cultivation may not be 
adapted to secure the best results. 
