103 



THE CHAIN OF LIFE. 



continents were in the st ♦^e of swampy and often submerged 

 flats, and in wliich the climate was again warm and uniform. 



The Carboniferous age was, even more emphatically than the 

 Devonian, an age of Acrogens and Conifers. A few Carboni- 

 ferous Fungi have recently been discovered, but there are no 





KiG. 94.- Structures of the oldest-known Angiospermous Exogen (Syringoxylott 

 mirabilc, Dn.J. From Jiighteen-mile Creek, Lake Erie, 



I. Transverse section X 100. 2 and 3. Portions of the same X 300. 4. Longitudinal 

 section X 300. 5. Fragment of duct from the same X 600. 6. Wood cells and 

 medullary ray X 600. 



known Lichens or Mosses. There see m to be a few Endogens, 

 but no true Exogens. The great bulk of the plants consists of 

 Acrogens and Gymnosperms, as in the previous period. As 

 this flora is so very important and so much better known than 

 any other of those belonging to the infancy of the vegetable 



