arranged in simple or compound umbels, and the main and subordinate
clusters may or may not be provided with involucres and involucels. To
this mode of arrangement there are exceptions. In marsh-penny-wort
(Hydrocotyle) the umbels are in the axils of the leaves, and scarcely
noticeable; in Eryngium and Sanicula they are in heads. The calyx is
coherent with the two-celled ovary, and the border is either obsolete
or much reduced. There are five petals inserted on the ovary, and
external to a fleshy disk. Each petal has its tip inflexed, giving it
an obcordate appearance. The common colors of the corolla are white,
yellow, or some shade of blue. Alternating with the petals, and
inserted with them, are the five stamens.

The fruit, upon which so much stress is laid in the study of the
family, is compound, of two similar parts or carpels, each of which
contains a seed. In ripening the parts separate, and hang divergent
from a hair-like prolongation of the receptacle known as the
gynophore. Each half fruit (mericarp) is tipped by a persistent style,
and marked by vertical ribs, between or under which lie, in many
genera, the oil tubes or vittae. These are channels containing aromatic
and volatile oil. In examination the botanist makes delicate cross
sections of these fruits under a dissecting microscope, and by the
shape of the fruit and seed within, and by the number and position of
the ribs and oil tubes, is able to locate the genus. It, of course,
requires skill and experience to do this, but any commonly intelligent
class can learn the process. It goes without saying, and as a
corollary to what has already been stated, that these plants should
always be collected in full fruit; the flowers are comparatively
unimportant. Any botanist would be justified in declining to name one
of the family not in fruit. An attempt would often be mere guesswork.

In this family is found the poison hemlock (Conium) used by the
ancient Greeks for the elimination of politicians. It is a powerful
poison. The whole plant has a curious mousy odor. It is of European
origin. Our water hemlock is equally poisonous, and much more common.
It is the _Cicuta maculata_ of the swamps--a tall, coarse plant which
has given rise to many sad accidents. _AEthusa cynapium_, another
poisonous plant, known as "fool's parsley," is not uncommon, and
certainly looks much like parsley. This only goes to show how
difficult it is for any but the trained botanist to