728 On the Natural Succession of the Dicotyledons. [ November, 
inee with the Oleacee, the Aguifoliacee with the Rhamnacee, the 
Malvacee with the Euphoritacee, and the Hamamelacee with the 
Platanacee. These comparisons-and others that will suggest 
themselves to every botanist, reveal natural relationships between 
plants which are far removed from each other because they fail 
to agree in the one character on which the divisions are based. 
They clearly show, therefore, that the arrangement by divisions 
is an artificial one, and that the fact of the coherence or non- 
coherence of the petals is far from a reliable one as indicating the 
true succession, much less the genealogical descent of the 
families. 
It is not claimed, however, that the three mostly parallel series 
wholly fail to express any general law of the vegetable kingdom, 
and. an attempt will be made before concluding the subject to 
show that they do express in a partial manner an important truth 
in phytonomy. Though concurrent for a great part of their 
length and inosculating all along, these lines of development 
appear not to have had a simultaneous origin. But before enter- 
ing upon the direct treatment of this problem it will be necessary 
to consider another class of facts. 
The practice thus far dwelt upon of distorting the natural 
system by an undue regard for the corolla is only one example 
under a general class. The vice itself expressed in general 
terms, is that of adhering too closely to any one character to the 
neglect of all the rest. We thus find cases within the same 
division in which orders unquestionably allied are not placed 
together, but are widely separated. Every one has been struck 
by the resemblance of certain Ranunculaceous with certain Rosa- 
ceous plants, especially as to foliage and general habit; for exam- 
ple, Ranunculus with Geum, Actea with Spiræa, etc. It iS, 
=- customary with botanists to affect a certain degree of contempt 
_ for such general resemblances, and they are commonly regar ded 
as wholly misleading. That they cannot be depended upon as 
safe guides to special investigation all will of course admit, since 
- it $ so frequently happens that striking similarities exist between 
families which cannot in any way be assimilated. But even in 
uch cases the resemblances often vanish on closer inspection and 
» have been produced by entirely dissimilar processes- 
rehine Aich will bear close inspection are rarely 
here is e certain correlation which subsists 
