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adaptation or mutation, or similarly to produce many others by crossing, but 
also are formed from. within or without by other means which are as yet 
unknown to man,—such minds can neither recognize the existence of the 
phylogenetic tree, nor believe in the possibility of phylogenetic classification. 
Moreover, for those who understand the real state of the natural relations 
of families as illustrated by the examples which we have just given 
above, it is impossible to believe the existence of any determined static 
natural system such as modern systematizers are unanimously struggling to 
make. 
There have hitherto been several systems” which have been called natural. 
But, all of them are static. The two most used by students at the present 
time are the systems of BenrHamM-Hooker and of Exeter. In both of these, 
speaking generally (certainly there are exceptions), one first group (say a family) 
is connected with a second by a relation established according to a certain 
view, while the latter is connected with a third by a relation established 
according to another view. The members of this part of the system are, 
therefore, considered from one point of view; but those of that part of the 
same system are arranged according to another point of view. For example, 
the members of the Monoctyledones are arranged regardless of whether they 
are gamopetalous or polypetalous ; while those of the Dicotyledones are arranged 
on the basis of the said characters”. Another example is found in the classi- 
fication of the Tubiflore. Some families of the latter series are on the one 
hand classified on the basis of whether they have or have not eremus; while 
others of the same series are, on the other hand, arranged on the basis of 
whether their flowers are zygomorphous or actinomorphous”. Accordingly, 
the present systems certainly cannot be taken as denoting natural relations 
of the members in every respect; nor are they systems that denote relations 
1) Among the systems which have been established by great authors, I may mention the 
following, namely :—The system of Lainnarus (1735); that of A. L. pz dussizu (1789) ; that of 
Aue. Pyr. pg Canponie (1819); that of Sr. Enpricuur (1836-1840); that of A. BroncNiaRtT 
(1843); that of Benrnam and Hooxer (1862-1883); that of Avex. Brauns (1864); that of Ap. 
Ercaugr (1883). That of Van Tracuem (1898); that of Avour Evcier (1912). ; 
2) Enouzr, A.— Exliuterungen zu der Ubersicht tiber die Embryophyta siphonogama, in 
Nat. Pfl.-fam. Nacht. I. p. 371. 
3) Enoier, A—1. c. p. 370. 
