5^2 
Sinnott and Bailey . — The Origin and 
Senecio (PL XXXIX, Fig. 12, and PI. XL, Figs. 14 and 16), its herbaceous 
representative will show but a slight exaggeration of the same thing 
(PI. XL, Figs. 13, 15, and 17). The whole process of reduction from a woody 
to an herbaceous condition is therefore a very simple and natural one. 
III. Evidence from Phylogeny. 
Still further evidence as to the relative antiquity of herbs and woody 
plants is furnished by a study of the distribution of these two types in the 
general system of Angiosperm classification which has been constructed by 
phylogenists. 
There are two main groups of Gymnosperms from one of which it 
is generally conceded that the Angiosperms have arisen. These are the 
Gnetales and the Bennettitales or ancient Cycads. The former are repre- 
sented to-day by three genera, a shrub, a woody liana, and an anomalous 
woody desert-plant. The Conifers, from which they seem to have sprung, 
are without exception woody forms and almost entirely arborescent. The 
Bennettitales, on the other hand, are typically Cycad-like in habit, and 
there is no indication that they were ever herbaceous. Primitive Angio- 
sperms, if they approached either of these two groups very closely, were 
therefore in all probability woody rather than herbaceous in habit. 
The history of the Angiosperm flower is as yet so uncertain that there is 
much difference of opinion as to whether the simple and almost naked- 
flowered forms, which may be grouped under the inclusive order Amentiferae, 
or such perfect-flowered types as the Ranales, are the most ancient members 
of the phylum ; but there is very general agreement of opinion that the 
distinction should belong to one of these two orders. As at present consti- 
tuted the Amentiferae are composed entirely of woody forms, with the 
exception of the Saururaceae and certain of the Piperaceae and Chlo- 
ranthaceae ; and the Ranales are also entirely woody, save for the* 
Ranunculaceae, certain of the Berberidaceae, and two aquatic families. 
If either of these two great orders contain forms which are very close to 
the original Angiosperms (and if these forms have maintained their ancient 
habit of growth), the chances seem entirely in favour of the view that the 
primitive Angiosperms were either arborescent forms or at least possessed 
well-marked secondary growth, and therefore were not herbaceous. 
Evidence in favour of the comparatively recent origin of herbs is also 
presented by a study of those families which include both woody and 
herbaceous species, and in which it is also possible to distinguish the 
primitive from the more recent members. 
The Leguminosae are an instance in point. The two sub-families 
Mimoseae and Caesalpineae, with their regular or nearly regular floral 
structures and frequently numerous stamens, are without much question 
more primitive than the Papilionatae, in which the corolla is typically 
