CHAPTER IV 

 PLANT LIFE 



As agriculture is the art of cultivating the soil so as to pro- A knowledge 

 duce crops from the various plants of use to man, it is neces- necessary! ^ 

 sary for the agriculturist to have a knowledge of all that 

 concerns the life of a plant. 



Most plants usually consist of five parts, namely, the root, 

 the stem, the leaves, the flowers and the fruit. There are 

 some plants, it is true, that have one or more of these parts 

 wanting, but it is unnecessary to consider them in this work, 

 for the tropical agriculturist is concerned mostly with the 

 ordinary flowering plants. 



The Root, which is called the descending axis of the 

 plant, varies very much in its character. In the grasses and 

 other plants, the roots consist of many fibres spreading out 

 in the soil in all directions ; some of them, indeed, are much 

 longer than the stem, as in the case of the maize — the roots 

 of which have been traced to the length of fourteen feet. 

 Other roots, called tap-roots, send a thick prolongation of 

 the main axis straight down into the soil, and give off small 

 fibres at intervals ; the best example of this is the carrot, but Functions of 

 coffee and cacao also possess tap-roots. Roots have two im- 

 portant functions : firstly, they fix the plant into the soil, or 

 to the substance on which it grows ; and, secondly, they 

 take up nourishment for the plant to live and thrive on. At 

 their ends all roots become very small and tender, and give 



