GLIMPSES INTO PLANT STRUCTURE 51 



in Fig. 33, taken from a plant commonly found 

 on moorland hills and known as "club-moss." This 

 is a tiny moss-like plant only a few inches in 

 height at the present day ; but many geological 



Fig. 34. The structure of a rush stem 



ages ago the ancestors of our club-mosses were 

 amongst the most prominent forms of the vege- 

 table kingdom, bourgeoning as large trees with 

 stems or trunks sometimes four and five feet in 

 diameter. Fossilised trunks of these great club- 

 mosses are often found amongst the coal measures; 



