CLASSIFICATION. 153 
atone excepted, (§ 143, No. 7). The three fol- 
lowini@ classes ave not always constant with regard 
to sex; a difference of climate will sometimes re- 
move a plant from the class Monoecia to that of 
Polygamia. 
Linjesap has made the followme changes on 
the Linnzan system. He joins the 7th, sth and 
9th classes to the 10th. His Decandria thus con- 
tains the Heptandria, Octandria, Enneandria and 
Decandria of Linneus.. The 11th class he joins to 
the 13th. ‘The 1sth, 21st, 22d, and 23d he m- 
cludes in one. ‘Thus his system contains only 
sixteen classes, viz. 
1. Monandria. 9. Polyandria. 
2, Diandria. 10. Gynandria. 
3. Vriandria. 11. Didynamia. 
4, ‘Yetrandria. 12. ‘Tetradynamia. 
5. Pentandria. 13, Monadelphia. 
6. Hexandria. 14, Diadelphia. 
7. Decandtia. 15, Syngenesia. 
8. Tcosandria. 16. Cryptogamia, 
Some other botanists have changed the orders of 
the 19th class, by leaving out the word Polyeamia, 
and removing’ the plants of the order Monocamia 
to’ other classes. 
But this order of the 19th class ought to be al- 
together suppressed ; because the genera belonging to 
it have nothing in common with the other syngene- 
sious flowers but the united anthera, which other 
genera, for instance the solanum, possess likewise. 
Uf this order be taken away the class becomes per- 
fectly natural. 
OCHREBER, 
