The Way in Which Plants Feed and Grow 17 



assimilable plant -food. This now diffuses downward 

 through the cells as the crude and more diluted liquid 

 rises, and the parts of the plant from leaf to root appro- 

 priate this prepared material to the formation of new 

 cells and through them to plant-growth. While the roots 

 are collecting food, in solution, from the soil, the leaves 

 are taking from the air, carbon and oxygen combined as 

 carbon dioxide (carbonic acid gas), which they dissect, 

 using the carbon as building material during the day, 

 giving the oxygen back to the air and reversing this 

 process at night, appropriating the oxygen and discarding 

 the carbon. It is thus shown that all parts of the plant 

 are mutually dependent upon each other. The roots col- 

 lect the soil -derived material and send it up to the leaves 

 to be prepared for food. It then diffuses to all parts of 

 the plant, the roots included, contributing to the growth 

 and development into a complete individual. This is the 

 simple story of the feeding and growth of the plant. 



SEXUALITY IN PLANTS 



Plants reproduce naturally by seed, bulbs, tubers, 

 underground stems, etc., but by far the most common 

 plan is through flowers, resulting in the production of 

 seed. 



Flowers of different species of plants differ materially 

 in the arrangement of the essential organs of reproduc- 

 tion. The three principal types are: 



Bisexual, or perfect flowers, having all of the essential 

 organs of reproduction in the same flower. Okra, beans, 

 and the cabbage family have perfect flowers. These 



