ALLIANCES OF PLANTS. 225 



This group touches Rhizanthese through Fungaceae. 

 Gymnospermae Lycopodales. 



Filicales. 



Characeae. 



If the affinities that have thus been explained are correctly stated, a mutual connection 

 of the five great classes in the vegetable kingdom may be expressed by a circle, in the 

 middle of whose circumference stand Exogens and Endogens, side by side ; the common 

 point of all the classes is formed by Acrogens ; which are connected on the one hand with 

 Exogens by Gymnosperms, and on the other with Endogens by Rhizanths. 



The following scheme will place this idea in a more distinct point of view : 



Aracets to Cynomoriaoea. 



w 



C'/Jvrant/taceee to Gnetacete. 



