xx CLASSIFICATION OF PLANTS. 
of them contains sections, of which there are in all 12 ; and though at 
first sight it may appear simple and easy of reference, it still presents con- 
siderable difficulties, from many of the characters being merely negative, 
and others by no means decisive. 
The systems, whether of Cesalpinus, Morison, Ray, or Tournefort, were 
all, more or less, attempts at a natural classification. We now come to the 
artificial system of Linnzus, the basis of which rests almost entirely on the 
male organs or stamens; and where no sexes could be distinguished, he 
termed the plants cryptogamous, and assigned to them the 24th class of 
his arrangement, Cryptogamia. His system is as follows :— 
I. Stamens Derinite anp Equat. 
1. Monandria; one stamen. 6. Hexandria; six stamens. 
2. Diandria; two stamens. 7. Heptandria; seven stamens. 
3. Triandria; three stamens. 8. Octandria; eight stamens. 
4, Tetrandria; four stamens. 9. Enneandria; nine stamens. 
5. Pentandria; five stamens. 10. Decandria; ten stamens. 
II. Stamens Inperrnire. 
11. Dodecandria; stamens from eleven to nineteen. 
12. Icosandria ; stamens twenty and upwards, perigynous or inserted 
on the calyx. 
13, Polyandria; stamens twenty and upwards, hypogenous or inserted 
on the receptacle. 
ITI. Stamens Unzgvat. 
14. Didynamia; stamens four, two longer than the others. 
15, Tetradynamia ; stamens six, four longer than the others. 
IV. Fitaments Unirep. 
16. Monadelphia; one bundle of stamens, or androphore. 
17. Diadelphia; two bundles of stamens. 
18. Polyadelphia; or several bundles of stamens. 
V. Aytuers Unitep. 
19. Syngenesia ; stamens five, united by their anthers, flowers collected 
into a common involucre. 
VI. Stamens vuytrep to tHe Prstrz. 
20. Gynandria. 
VII. Frowers Unisexvat. 
21. Monecia; stamens and pistils on the same individual. 
22. Diecia; stamens and pistils on different individuals, 
23. Polygamia ; herm ite and unisexual flowers, either on the 
same or different individuals. . 
‘VIII. Frowrars Invistsre. 
24. Cryptogamia ; neither stamens nor pistils. 
In the first thirteen classes the characters of the orders, or subdivisions 
of the classes, are derived from the number of the styles or female organs, 
