CHAEACTEES USED IN CLASSIFICATION. 
123 
155. We have found that Tournefort considered chiefly differ- 
ent aspects and circumstances of the corolla / — Linnaius, of the 
stamens SLudpistUs / — Jussieu, of the cotyledons^ and insertion of 
the stamens. Tournefort's system was defective, as the forms of 
corollas are often indefinite, and blend into those of an opposite 
character ; that of Jussieu appears too abstract to be used inde- 
pendently of the aid of some more simple method ; — the number 
of cotyledons^ though a definite and important character, cannot, 
in many cases, be determined without the slow process of wait- 
ing for the seeds to germinate ; the insertion of stamens and of 
the corolla often appears doubtful, even to the experienced 
botanist. The characters used in the system of Linnseus are 
ajpjparent^ referring to the number of parts, rather than to 
their forms or insertion / this ofiers to the mind something 
positive^ which is not found in any other method. Between a 
corolla hellform or funnelform there are many intermediate 
forms^ which may be as much like one as the other. The in- 
sertion over the germ or under the germ is distinct, but the 
insertion around the germ sometimes blends with one, some- 
times with the other mode. But, hetween one or two stamens^ 
or one or two pistils^ there is no intermediate step or gradual 
blending of distinctions. 
The Linnsean system, in practice^ is by no means perfect. In 
treating of the classes in detail, we shall point out cases in which 
it widely separates plants similar in appearance and properties, 
and brings together, from the mere circumstance of similarity 
in stamens, plants wholly unlike in other respects. The im- 
provements of Lindley and other botanists upon the method of 
Jussieu, we shall hereafter consider. 
LECTUKE XXIII. 
CHARACTERS USED IN CLASSIFICATION. 
156. LiNN^us, in his "Philosophy of Botany," established 
three hinds of characters to be used in the description of plants. 
Factitious (or made) ; that which is, by agreement, taken as a 
mark of distinction ; thus, certain circumstances with respect 
to stamens and pistils are fixed upon for distinguishing classes 
and orders. Although nature has formed these organs, the 
arrangement of plants by their means is an invention of man. 
155. Comparative merit of the three methods— System of Linnaeus offers something positive — !• noi 
perfect. — 156. Three kinds of characters to be used in desciiptions of plants. 
