1G2 
NATURAL FAMILIES. 
as a rose can be more easily distinguished from a pink, than 
one species of rose from another species. Families are grouped 
together by marks of resemblance found in genera. 
These family characters are of all the most important. 
In the artificial classes and orders we depend on what we 
have before termed factitious characters. 
In species genera and families, the essential characters, are 
also natural characters. 
LECTURE XXII. 
Natural Families. 
In the view of natural families which we are now to give, we 
shall follow the divisions of both Jussieu and Linnaeus, as they 
shall appear best adapted to answer the purpose of arrangement. 
The method of Jussieu being however, more philosophical than 
the natural method of Linnaeus, we shall chiefly follow the clas- 
sification of the former. 
Class 1. 
Acotyledons.* Embryo destitute of cotyledons, and a separate 
albumen. 
We find in this class, plants which are contained in the class 
Cryptogamia of the artificial system. Fungi , or mushrooms ; 
these are either parasitical, or spring from the ground naked or 
enclosed in a volva. The substance of mushrooms is in some, 
like cork or leather, in others soft, fleshy and juicy. They are 
round or flat ; some have a head called a pileus (signifying hat.) 
They have neither leaves or flowers. Instead of anthers they 
have a scattered, external or internal powder. Instead of pistils 
they have organs, which resemble thin plates, wrinkles, pores, 
tubes, &c. In these organs exists a substance analogous to seeds, 
which germinates and reproduces the species. The different 
species of fungi are known by the common names of toad-stool, 
puff-ball, &c. 
The class without cotyledons contains several other families ; 
of the remainder you are perhaps best acquainted with mosses 
and ferns. 
* From a without, and cotyledon, signifying' destitute of cotyledon. 
Synopsis of Jussieu. Class first — Acotyledons — Embryo destitute of 
cotyledons and separate albumen — family, Fungi — Mushrooms. 
