LIFE 



459 



modern horse-tails, except for their large size. The largest modern 

 tropical representatives of the group have slender stems 30 or 40 



'feet high, whereas the Pennsylvanian calamites reached a foot or 

 two in diameter and probably 60 to 90 feet in height. They had 

 hollow stems, or a core of pith, and casts of the interior are common. 

 Branches from the trunk were comparatively few, and in whorls. 



V 



- 395- A composite group of leading CAKHOMI i ROUS PLANTS, adapted 

 from restorations by various paleobotanists, by Mildred Marvin. In the fore- 

 jund at the right, Lcpidodetidron; at the left Si%illaria; in the right center rear, a 

 fern; in the left center rear, Cordaites; at the extreme right and left, Calamilcs. 



"he leaves also were in whorls (Fig. 395) and dwarfed, though 



irger than in the modern type. Their roots were of the type 



commonly found under water or in wet places, and the calamites 



probably frequented swamps and lowlands. Roots are known to 



have been sent out as much as nine feet above the base of the stem. 



