202 THE EVOLUTION OF PLANTS 



of any living Spore-plant. They were usually 

 borne at the ends of twigs (see fig. 22), but in the 



Fig. 22. Palceostachya arborescens. Branch of a Calamite, 

 bearing large cones. After Weiss. 



case of some of the largest cones, which reached 

 a length of eight inches, the arrangement was in 

 whorls, on the main stem or a stout branch. 



