54 BOTANY. 
E. Class XIX. subdivides into : 
Order 1. Polygamia equalis: florets all hermaphrodite. | 
Wa “« _superflua: florets of the disk hermaphrodite, those of the 
ray pistilliferous and fertile, 
RB. a frustranea: florets of the disk hermaphrodite, those of the 
ray neuter. 
Samer as necessaria: florets of the disk staminiferous, those of the 
ray pistilliferous. 
aud ie segregata: each floret having a separate involucre. 
“ 6. Monogamia. Anthers united, flowers not compound. 
EF. Classes XX. to XXII. subdivide into : 
Orders: Monandria, Diandria, &c., according to the number of stamens. 
G. Class XXIII. subdivides into : ; 
Order 1. Moncecia: Hermaphrodite, staminiferous, and pistilliferous flowers on 
the same plant. ; 
“« 2, Dicecia: the same on two plants. 
“« 3. Tricecia: the same on three plants. 
H. Class XXIV. subdivides into: 
Order 1. Filices: Ferns. 
“ 2. Musci: Mosses. 
“ 3. Hepatice : Liverworts. 
« 4. Lichenes: Lichens. 
« 5. Alge : Seaweeds. 
« 6. Fungi: Mushrooms. 
The object in the natural system is to combine those plants which are 
allied in essential points of structure. Every natural method is, however, 
to a certain extent artificial, and it will be impossible to construct a perfect 
natural system until all the plants of the globe are known. ‘The first natural 
system of much special value was that of Jussieu, published in 1789. This 
includes one hundred natural orders or groups of genera, the whole arranged 
under fifteen classes, as follows : 
NatTurAL SYSTEM ACCORDING TO JUSSIEU. 
Class 
ACOTYLEDONES, : : : : ; : nme tare : - : : 4 : 
( Mono-hypogyne (Stamens hypogynous), . : : : oe 
MonocoTyLeponEs, 4 Mono-perigyne ( “  perigynous), . ; : , . III. 
| Mono-epigyne ( “  epigynous), . A ‘ : Aig ee 
Epistaminee (Stamens epigynous) V. 
Apetalze Peristaminee( “ perigynous) VI. 
Hypostaminez ( “ hypogynous) VII. 
| (No petals) 
Hypocorolle(Corollahy pogynous) VIII. 
Pericorolle ( “ perigynous) IX. 
| Monopetale 4 (Synanthere . X. 
a Monoclines { (Petals united) | (anthers united) 
DicoTYLEDONES, (Sowers united) Epicorolle : 
| (Corolla epigynous) | Corisantheree . Mt. 
[ (anthers free) 
l 
(Epipetale (petals epigynous). XII. 
Polypetale 4 Peripetale ( “ perigynous). XIII. 
| (Petals distinct) | Hypopetale( “ hypogynous). XIV. 
Diclines (flowers unisexual or without a perianth). : : XV. 
54 
