76 
W. G. Freeman. 
is attained to-day, namely, by experiment, observation and 
inference. That the so-called savage does deliberately apply this 
method, was brought to my notice in a striking manner, only a few 
months ago, in an uncivilized portion of West Africa, where I found 
that localities for native “ farms ” were selected by the experimental 
planting of a few yams or a small patch of Indian corn, and 1 
frequently saw in the “ hush ” little cultivated patches, often only a 
few yards square, which were evidently native experiment plots. 
The study of systematic botany can he traced hack to the 
search after plants for their economic uses. Sachs points out in 
the opening lines of his History of Botany, how “the authors of 
the oldest herbals of the 16th century regarded plants mainly as 
the vehicles of medicinal virtues: to them plants were the 
ingredients of compound medicines, and were therefore by preference 
named simplicia." He describes how the labours of the first 
German composers of herbals who went straight to nature, 
described the wild plants growing around them, and had figures of 
them carefully executed in wood resulted in the first beginning of a 
really scientific examination of plants. “ In the effort to promote 
the knowledge of plants for practical purposes the impression 
forced itself on the mind of the observer that there are various 
natural groups of plants which have a distinct resemblance to one 
another, in form and other general characteristics.” 
Practice was in advance of exact knowledge in the appreciation 
of the beneficial action of leguminous plants. Again, the vexed 
question of the use of shade trees in tropical agriculture has had 
considerable light thrown upon it by the recent generalization that 
the time-honoured shade trees, with few exceptions, are members 
of the Leguniinosae. In some cases the shade was no doubt 
directly beneficial, in other cases harmful, but in the latter the net 
result might still be beneficial owing to the counterbalancing 
action of the trees in increasing the fertility of the soil. The 
important results obtained in the remote past, have already been 
alluded to. For a comprehensive account, the classical work of 
De Candolle On the Origin of Cultivated Plants should be consulted. 
In the following table an attempt has been made to indicate, at a 
glance, the duration of time through which some of the more 
economic plants have been cultivated :— 
Cultivated for more than 2000 years. 
Cereals. 
Wheat. Barley. 
Oats. Millet. 
Sorghum. Rice. Maize. 
