NATURAL FAMILIES. 
157 
2d. Essential Character. Thai which forms a particular char- 
acter of one genus, and distinguishes it from all other gen- 
era. 
3d. Natural Character. This is difficult to define, but it is that 
which is understood by all; it is the general aspect and ap- 
pearance of the plant which enables all persons to make a 
kind of arrangement of plants in their own minds, although 
they would find it very difficult to convey their ideas of 
classification to others. 
It is by their natural characters that persons who have never 
perhaps heard of such a science as zoology or the classification 
of animals, are enabled to distinguish ferocious beasts from do- 
mestic and gentle animals ; they see a sheep or a cow, although 
that individual one they may never have seen before, without 
any terror, for nature teaches them at once to consider that as 
resembling other sheep and cows which they know to be inof- 
fensive. 
This natural character teaches savages to distinguish among 
the many plants of the forest, those which may administer to 
their wants and those which would be injurious. 
Even the lowest grade of animals appear 1o have this faculty 
of selecting by natural characters nutritious substances, and 
avoiding noxious ones. How often do animals, feeding in pas- 
tures which contain poisonous plants, pass them by, to seek 
the grass which seems made for their use, and this instinct is 
kindly given for their preservation. 
LECTURE XXL 
Comparison of Natural and Artificial Classes. Characters 
used in classification. 
A natural family is composed of several genera of plants 
which have some common marks of resemblance, and its name 
is usually founded upon this general character ; as Labiate gnd 
Cruciform, which are derived from the form of the corollas ; 
Umbellate and Corymbiferous, from the inflorescence ; Legu- 
minous from the nature of the fruit. 
Families resemble artificial orders in being composed of gen- 
era, but the principles on which the genera are brought together, 
differ widely in two cases. 
Essential character — Natural. 
Families of plants — Families resemble artificial orders, being composed 
of genera. 
14 
