8 General Botany 



stems, and leaves, all those processes which are related to the 

 nourishment of the plant are carried on. 



In the course of the plant's life three other organs are developed. 

 These are the flower, fruit, and seed, which are the reproductive 

 parts. The flower is usually very different in structure, texture, 

 and color from the vegetative parts and also much shorter lived. 

 The fruit follows the flower and is usually developed by the con- 

 tinued growth of one or more of the parts of the flower. Within 

 the fruit are the seeds. They are commonly small bodies con- 

 taining within them a young undeveloped plant (embryo) and 

 a food supply. Seeds can withstand cold and drying; so, in 

 addition to multiplying the plant, they carry the species through 

 winters and periods of drought. Under favorable conditions 

 they germinate and reproduce the plant from which they sprang. 

 Flowers, fruits, and seeds are reproductive organs. 



Interdependence of the parts of a plant. The roots, stems, and 

 leaves make up the plant's machinery of nutrition, and the nour- 

 ishment of the entire plant depends upon each part doing its 

 work. If the roots are broken, the water supply is cut off and the 

 leaves wither. If the leaves are removed, food manufacture 

 stops and all the parts die for lack of nourishment. If the con- 

 ducting vessels in the stem are cut, the water supply to the leaves 

 fails and the roots have no food. The farmer destroys bushes 

 by keeping them cut down so closely that they cannot expose 

 leaves to the light, and he knows how to kill trees by cutting a 

 ring about them through the bark, so that food cannot pass from 

 the leaves to the roots. 



It will thus be seen that when we discuss the relation of any 

 particular part of a plant to the energy-supplying and nutritive 

 processes, we must ever keep in mind the interrelation and inter- 

 dependence of ah parts of the plant. Just as no part of the 

 human body lives an independent life but is dependent for its 

 welfare on the activities of all the other parts, so the Ufe of each 

 part of a plant is bound up with the life of the plant as a whole. 



