125 
quently, groups of plants whose characteristics mostly occur in correlation are less 
changeable ; while groups of plants whose characteristics usually occur indepen- 
dently are more changeable. Such families as the Orchidacese and Gramines 
belong to the former, while such as the Loganiacew and Myoporacee approach 
the latter class. 
What he state in §§ 21 and 22 is, in brief, that on one hand he regards 
characteristics in linkage - relation as those denoting the serial orders of advance- 
ment and gives them a high systematic importance, but on the other hand 
he puts no value on the characteristics which occur independently and without 
-regard to others. But, in this I cannot concur. In my opinion, we ought 
to take into consideration for classification all characters without being partial 
to any of them. 
The perianth characters to which he refers in § 23” are the most important, 
as far as present systematic botany is concerned. But when we ask why 
they are so appreciated, no reason is forthcoming. There is nothing but con- 
vention to support the practice, as I have already explained. 
In § 24 he says :— 
Mit Ausnahme sehr weniger Fille liegt bei den Angiospermen Klar zutage, daf 
die Formen mit Zwitterbliten phylogenetisch ilter sind, als die sonst sich gleich 
verhaltenden mit eingeschlechtlichen Bliiten, Diese Progression tritt wnendlich 
oft ein und ist zur Gruppenbildung kaum zu verwerten. 
But why is it that the characters of bisexual or unisexual flowers that show, 
as he expresses it, a serial advancement can not be appreciated as having 
high systematic value? This is, in my opinion, only because of insisting upon 
a static system. According to the dynamic view of a system, there can be 
no character that can not be so appreciated. 
In §§ 25 and 26”, he refers to many characters showing serial progression. 
He puts systematic value on some of these, but not on some others. But 
what is the reason of such partial treatment of characters? It is, as far as 
I can judge, merely because of an unquestioning acceptance of the present 
static system, which would of course at once be violated by the fair apprecia- 
tion of all characters. 
1) Evxourn, A.—J. v. p. XVI 2) Enorer, A.—l c. p. XVIIL 
