420 



THE ANATOMY OF WOODY PLANTS 



of periodic growth is, however, frequently found in regions of higher 

 latitude than that portrayed in Fig. 288. The next illustration 

 shows the organization of a Carboniferous cordaitean wood (Mesoxy- 

 lon) from the northern part of England and consequently of consider- 



FIG. 289. Details of wood structure of Mesoxylon (Cordaites) with annual rings. 

 Tangential pitting is absent. 



ably higher latitude (54 N. in contrast to the 46 N., the latitude of 

 Prince Edward Island). The annual rings in the wood from the 

 English Carboniferous are clearly marked. The next illustration 

 (Fig. 289) reproduces the minute organization of the same wood 



