WOODLANDS 267 



phytes, apart from a few ferns (e.g., Poly podium vulgar e). 

 mosses, liverworts, and lichens, are mostly accidental. 

 Lianes, or woody climbers, which form such a character- 

 istic feature of tropical forests, are merely represented in 

 our woods by the honeysuckle, ivy, and clematis. Many 

 of our forest- trees, living in soil rich in humus, are partial 

 saprophytes, their roots being clothed with a mycorhizal 

 fungus instead of root-hairs (see p. 124). 



Natural and Artificial Woods. 



These islands were once far more extensively wooded 

 than they are now, although it is still a well-wooded 

 country. Most of the huge forests which once covered 



FIG. 112. THE SAME WOOD AS IN FIG. Ill, SHOWING DISTRIBUTION OF 

 BRACKEN. (AFTER WOODHEAD.) 



] . 1 1 1 1 Pteris aquilina (bracken). 



the land have been cut down for economic purposes, or 

 cleared to make way for cultivation and pasture. Much 

 of what remains has been seriously interfered with and 

 modified by man, by periodic cutting and replanting, and 

 in many places new woods have been planted on arable 

 land and pasture. Artificial woods are not always easy 

 to distinguish from natural woods, especially when they 

 are old-established, and felled portions have been re- 

 planted with trees native to the soil and common to the 

 district. Natural woods regenerate themselves by seed, 

 and in them trees are seen in all stages of development ; 



