Agricultural Botany. 575 
Just as the dominant motives in nature have secured fixity for 
types, so the dominant motives under art have secured fixity of 
type, but as the motives differ, so do the types differ. Hence 
natural botany cannot serve to secure classification for plants 
which have become domesticated, and for these latter we require 
anew botany, which we may call agricultural botany, and which 
must be devised alike in its principles with natural botany, but 
divergent in its methods of application in accordance with the 
divergent plant-motives. 
In agricultural botany as in the natural botany, heredity 
must be considered in arrangement, for a true classification must 
deal with the totality of plant structure, form and motives, yet 
while in natural botany the reproductive organs, the expression 
the paramount motive given to the plant by nature, must be 
considered paramount for the purposes of classification, in agri- 
cultural botany form must be considered as paramount as repre- 
senting the paramount motive supplied to the plant by man. In 
the natural botany, species, genera, orders and classes represent 
Stages in the development under nature, in the agricultural botany 
Successive changes in selection represent stages in the life history 
of the new plant. | 
Premising that our remarks will be understood to apply to 
agricultural plants alone, we can illustrate our position by out- 
a classification for roots. 
When a wild plant is brought, through its seed, to the garden, 
and grown in rich soil and protected from weeds, the change in 
Size of the root may be at once manifest, and the root may be 
Smoother and less branching than in the plant under natural con- 
ons, but the type of form of root remains the same even under 
woe of Continued cultivation, unless modified by the pro- 
Selection. These protected, yet not domesticated roots, 
ture in common: the diameter of the root in its 
“PPer Portion does not exceed the diameter at the stem and leaf 
alae Examples are the Scorzonera, salsify, Scolymus and 
aa... F; 1g. I, Scolymus, and salsify, represents the type, of 
ON salsify is at the farthest remove towards improvement. 
| Plants become feral without change in the type of root. 
2 ene res domesticated roots, we find two separate classes 
The aS with, in some measure, like selections within both. 
first includes the ta d the caudate 
P-rooted forms, the secon e 
