Groups into Which Plants Naturally Fall 449 



four survived; (a) the Chemosynthetic Bacteria, whose persistence 

 to this day is shown by the continuous line sweeping up and off to 

 the outer rim of the tree where lies the vegetation of this, our own, 



Gamopetalous 

 Dicotyledons 



Polypetalous 

 Dicotyledons 



Apetalous Trees 



Monocotyledons 



Basidia Fungi 



Slime 

 molds 



Eoprotista. 



FIG. 177. A genealogical tree of the principal groups of plants. The axial lines show the 

 supposed relations of the groups at the time of their original evolution from one an- 

 other, while the solid trunks show their present numbers and connections. 



day; (b) the Animals, a vast group, shown on the left by an un- 

 finished stump which it is some zoologist's business to finish if 

 he wants it; (c) the Slime-molds, well described by their name, a 

 group of very simple organisms which creep as white films over 



