50 
CONTRIBUTIONS TO BOTANY. 
vve have fail’ evidence^ that both placentae and ovules must have 
proceeded from an immediate expansion of the elementary petioles 
of the original carpellai'y leaves. We perceive indeed, among 
the Cionospermce, a gradual deviation from this extreme, begin- 
ning with slight parietal rudiments of sterile dissepiments, about 
the base of the cell, and varying in degree, until we reach the 
oppositely extreme cases of the Styracece and Humiriacea, where 
the ovarium is many-celled, even to the apex ; but even here, in 
spite of the converging and always thickened incomplete dissepi- 
ments, extending so far, as even almost to touch the central ex- 
pansions, we find the ovuligerous placentae in the axis, always 
quite free from them, and from the style. If no original differ- 
ence is to be found in the nature of the development, between 
the plurilocular germen, and the one-celled ovarium with free 
central placentae, or if the existence of the latter were due to 
the breaking away from the placentae of the inflected portions of 
the dissepiment so formed, we should sometimes perceive in the 
same order, the same genus, or even in the same individual, some 
instance where this had happened in a greater or less degree, and 
we should often meet with the two structm’es confounded ; but 
we find invariably an equally uniform amount of development, 
proving that in their normal origin they are distinct. 
It was upon these views I drew the conclusion and offered 
as the most probable suggestion {huj. op. p. 27) that the nearest 
affinity of the Icacinacem is with the CelastracecE, or the Aqui- 
foliacea, but that they differ from these in many essential re- 
spects, and cannot be held to be subordinate to either of 
them. With those who think it tends to the simplicity of 
the science, to diminish to the utmost possible extent the pre- 
sent number of natural orders, the Celastracea, Aquifoliacece, 
Icacinacea, Hippocratacem and some others might be considered 
as suborders of one large family; but I do not perceive any 
advantage in this method ; for it matters little whether such 
divisions be called classes and orders, or orders and suborders ; 
for were such an order established (under the name, for 
instance, of the Dryacets), it is clear that, in practice, any 
plant traceable to such alliance would always be referred to its 
oum peculiar suborder and never to such family. I therefore 
incline to the greater convenience of retaining each group as 
hitherto established, as a distinct ordex’, and combining the whole 
in a class that may be called the Dryales^, because they mostly 
consist of trees with evergreen leaves. They cannot consistently 
be retained in the class of the Frangulacece of Endlicher, which 
are marked by other very different characters. 
The gi’oup of the Dryales will hence consist mostly of ever- 
green trees with alternate, rarely opposite, exstipulate leaves 
* From hpvs, arbor sempervirens. 
