95 
foliage leaf, in the case of the former, nor a primitive form, in the case of 
the latter. But it is the real entity which is itself an organ or species. We 
say this organ and that organ are different. Yet, they are different only in 
phenomenal appearances; in real entity, they are always similar. The same 
holds good as to species. If the proper conditions according to the causal 
nexus™ are posited, it is possible to derive any organ or species whatever 
from any organ or species. Therefore, when we interpret GoETHE’S Blatt or 
Urpfianze as the simplest fundamental organ or the most primitive organism, 
then the changes of organs or species are determinable and static. When 
we interpret, on the contrary, the Blatt or Urpflanze as a real entity, 
then the changes of organs or species are different in their courses according 
to the time and circumstances, and therefore are indeterminable and dynamic. 
Accordingly, the former interpretation is the view of evolution which finds the 
origin in one sole thing ; while the latter is the view of manifold interrelation 
of organs or species, which finds the origin in every thing. According to the 
former view, the relation of organs or species is explainable by the evolution 
theory, and the system denoting the relation should be a static one. By the 
latter, on the contrary, the relation is elucidated by the participation theory, 
and the system should be a dynamic one. The former finds its proof in the 
sole way of the changeability of organs or species. But the latter finds 
realization in the manifold views of the mutability of organs or species. 
The principle of natural classification should be founded on the latter 
views, namely :—on the participation theory, the dynamic system, and the 
manifold views of the mutability of species. As to the dynamic system of 
natural classification, I shall write more fully in the following paper. 
* By causal nexus, I mean the relation of innumerable causes, of which we know but a 
few. As a few causes of the formation of species, so far as are known to us, I may mention 
the following, namely :— the fixation of the characters acquired by the adaptation and direct in- 
fluence of external conditions; crossing, and mutation. These are by no means independent, 
but closely inter-related one to the others. Cf. Wertstey, R. R. — Handbuch der systematischen 
Botanik, p. 49. 
