THE SORTING OF PLANTS AND ANIMALS 



77 



64. The main groups of plants. The chief groups of plants 

 are indicated in the following outline : 



BRANCH I — THALLOPHYTES. Plants showing no differentiation into 

 true stem and leaf. 



•J' 







mi- 

 UI4 





Fig. 40. Reproduction in moss 



a, a leafy moss plant (Hypnum moUuscum)\ b, section cut lengthwise through tip of 

 one of the branches, showing position of archegonia, or egg-bearing organs; c, single 

 archegonium, more highly magnified, showing single large egg cell; d, enlarged view 

 of antheridiiim, or sperm-bearing organ, of Polytrichiim jormosum, discharging 

 sperm cells; e, greatly magnified view of sperm cells; /, tip of leafy plant from the 

 archegonium of which a spore plant has grown, showing stalk and spore capsule 



A. ScHizoPHYTES ('' Splitting plants ")• Each cell splits into two; no 

 other reproduction. 



1. Cyanophyceae. Splitting plants with chlorophyl — the blue- 



green algas. (Examples. Oscillatoria, Rivularia, Nostoc.) 



2. Schizomycetes. Splitting plants without chlorophyl. This group 



includes all the bacteria. 



