CLASSIFICATION OF PLANTS. 219 
practical value ; showing, by the use of the microscope, that the 
law was applicable not only to the external parts of plants, but to 
the development of their tissues also. Besides the debt which 
science owes to Robert Brown, he contributed largely to perfecting 
the natural method of classification. His great work upon the 
Hora of Australia has greatly extended the circle for that com- 
parison of characters which is the basis of ‘botanical genera and 
tribes, 
The number of families admitted in the present day as the result 
of the investigations of the eminent men whose names have been 
mentioned, and many others which could not be quoted here 
without swelling our pages to undue proportions, number THREE 
HUNDRED AND THREE ; and many of these are again subdivided by 
botanists who have made certain families their special study. 
We have had a tabular view of the vegetable world as arranged 
by Adrien de Jussieu. According to the modifications introduced 
by De Candolle, plants are divided into two great classes, Crypto- 
gumes and Phanerogames. 
The Crryprocamra, from ydpoc, nuptials, and ypumrdc, hidden, are 
destitute of pistils and stamens: they are reproduced by means of 
divers organs which seem to have no other analogy, except by their 
functions, with the reproductive organs in other plants. They 
Present no cotyledon, and yet they cannot be classed among 
acotyledonous plants. 
e PHANEROGAMES, from yéo¢ and pavepéc, visible, have per- 
ceptible reproductive organs formed of stamens and ovules, naked 
°r enclosed in a kind of pistil. 
According, then, as Phanerogames have an embryo furnished 
With one or two cotyledons, they are divided into two great natural 
8roups, the Monocotyledons or Dicotyledons. 
Adrien de Jussieu divided the Cryptogames, as we have seen, 
to two classes: Cellular Cryptogamia, including those composed 
of a vegetable tissue only, not traversed by vessels; and Vas- 
ove Cryptogamia, those provided with vessels. As regards 
hanerogamia, he arranged them in one great division, calling 
= Monocotyledonous Phanerogames ; distributing them, however, 
into two classes—(1) Gymnospermes, or naked-seeded, from yupvec, 
naked, and orépua, seed; and (2) Angiospermes (plants with seeds 
in 
