PAST HISTORIES OF PLANT FAMILIES 



147 



genus of plant called Calamites, which were very abundant 

 in the Coal Measures. Many of the Calamites were of 

 great size, for specimens with large trunks have been 

 found 30 ft. and more long, which when growing must 

 certainly have been much taller than that. The number 

 of individuals must also have been very great, for casts 

 and impressions of the genus are among the commonest 



A ft 



Fig. 104.— Small Branches attached to stouter Axis of Calamites. Photo of Impression 



fossils. They were, in fact, one of the dominant groups 

 of the period. Like the Lycopods, the Equisetacese 

 reached their high-water mark of development in the 

 Carboniferous period; at that time the plants were most 

 numerous, and of the largest size and most complicated 

 structure that they ever attained. 



As will be immediately suspected from analogy with 

 the Lycopods, they differed from the modern members 

 of the family in their strongly developed anatomy, and 

 in the strength and quantity of their secondary wood. 



