Cuass I. DICOTYLEDONS. 
Stem, when perennial, consisting of a pith in the centre, of one 
or more concentric circles containing fibrous tissue, and of the 
bark on the outside. Seeds with two cotyledons, the young stem 
in germination proceeding from between the two lobes of the 
embryo, or from a notch in its summit. 
The above characters are all that can be said to be constant to 
separate Dicotyledons from Monocotyledons. They are, however, in most 
cases very difficult to observe, and yet the distinction is essential, for 
these two great classes have each their peculiar aspect, which, after a 
very little habit, the botanist will in most cases recognise at a glance. 
All British trees and shrubs are Dicotyledons, so also are all plants with 
opposite, or whorled, or netted-veined leaves (except Paris and a few 
aquatic plants), and almost all those which have the parts of the 
flower in fours, fives, or eights. [For other characters see p. Ixxv.] 
I. RANUNCULACEA, THE RANUNCULUS FAMILY. 
Herbs with alternate or radical leaves, or, in one genus, 
climbers with opposite leaves, the leafstalk generally dilated at 
the base without stipules, the leaf often cut, and the flowers 
solitary or in terminal racemes or panicles. Sepals distinct, 
more than 2 (usually 5). Petals distinct, usually 5, but some- 
times deformed, or very minute, or wanting. Stamens indefinite, 
usually numerous, inserted on the receptacle. Carpels several, 
distinct or partially united (very rarely solitary), each enclosing 
a single cell, with 1 or more ovules or seeds attached to the 
base or to the inner angle of the cavity. Seed containing a 
copious albumen, with a minute embryo. 
Although, from the variable nature of the flowers, especially of the 
petals, the above characters may be somewhat vague, yet the great 
majority of Ranunculacee are easily distinguished by their numerous, 
free, hypogynous stamens, and by their distinct carpels. Where, as in 
Myosurus, the stamens are few, the carpels are numerous ; and, on the 
other hand, if in Actea and some Delphinia the carpels are solitary, they 
are unilateral, with the ovules attached to one side or angle of their 
single cell, showing that they are simple, not composed of the union 
of several, as is the case with the central ovaries of Papaveracee and 
Cistacew, which have either several cells or several rows of ovules. 
Another very distant Order, which may at first sight be confounded 
A 
