296 ELEMENTARY STUDIES IN BOTANY 



ing of crops checked the roaming of men, and they began 

 to " settle down " and cultivate definite areas of land. In 

 this way, tribes of wandering hunters became transformed 

 gradually into groups of farmers. One of the most ancient 

 occupations of men, therefore, was the cultivation of plants. 

 When one considers the many thousands of kinds of plants, 

 it is a surprise that only a few hundred have been selected for 

 cultivation in the whole history of the human race. The 

 reason is that the few selected have supplied the needs of the 

 human race, but there is a rich, unworked mine in the thou- 

 sands of plants that have not yet been brought into 

 cultivation. 



2. Cultivated plants. The first plants cultivated seem 

 to have been the cereals. The grains of certain wild grasses 

 attracted attention as suitable for food and easy of cultiva- 

 tion, and thus the cultivation of wheat, oats, barley, and rye 

 began. These grasses, apparently the first selected, have 

 continued to be cultivated as exceedingly important food 

 plants. Later, other grasses came into cultivation as food 

 plants, notably rice and corn, and thus our most important 

 cereals were assembled. A further addition to the list of 

 cultivated grasses was made when the need for crops of hay 

 as food for domesticated animals was developed. For this 

 purpose, suitable meadow grasses were selected, but they have 

 not been cultivated with the definiteness and care that have 

 been given to the cereals. The reason for this has been that 

 meadow grasses occur abundantly in nature, suitable both 

 for grazing and for cutting; and in addition to this, plants 

 of other groups have been found to be extremely valuable as 

 forage plants (that is, suitable for stock), as clover and alfalfa. 



3. Agriculture and horticulture. The cultivation of the 

 cereals and of the forage plants is the work of the farmer, and 

 is included in the practice called agriculture. This word 

 means " field-cultivation," and has come to include not 

 merely the field-cultivation of food plants, but also the culti- 



