LINN-ffiAN SEXUAL SYSTEM. 77 



Class 18. Polyadelpliia : Filaments united into more parcels 

 than two. Orders: 1. Dodecandria; 2. Icosan- 

 dria, SEC. as before. 



Class 19. Syngenesia: Anthers united into a tube. Orders: 

 1. Monogamia, flowers solitary; 2. Polygamia, 

 flowers in heads. Sub-orders of the latter: 1. 

 u3qualis, florets all equal ; 2. Superflua, florets 

 of the disk complete, of the ray female ; 3. Frus- 

 tranea, florets of the disk perfect, of the ray 

 neuter ; 4. Necessaria, florets of the disk male, of 

 the ray female ; 5. Segregata, florets each with its 

 own proper involucre. 



Class 20. Gynandria : Stamens and styles consolidated. Or- 

 ders: 1. Monandria, &c. as before. 



Class 21. Monoecia: Stamens in one flower, pistils in another, 

 on the same plant. Orders: 1. Monandria, &c. as 

 before. 



Class 22. Dicecia : Stamens in one flower, pistils in another, 

 on different plants. Orders: 1. Monandria, &c. 

 as before. 



Class 23. Polygamia: Stamens and pistils separate in some 

 flowers, united in others, either on the same plant 

 or on two or three different ones. Orders: 1. Mon- 

 cecia, &c. as before. 



Class 24. Cryptogamia : no apparent flowers. Orders : Fi- 

 lices, Musci, Hepaticse, Algae, Fungi (592). 



