THE STORY OF THE LICHENS 119 



seen in the fanailiar Usnca, of drooping habit, 

 to which reference has already been made. In 

 its young days the Usnea usually displays a 

 fairly upright manner of growth, with stiff, grey 

 tufts. Another lichen which will be found on 

 tree trunks very frequently in company with 

 the Usnea is that known as Evernia pru- 

 nastvi. This Uchen generally grows in a pen- 

 dulous manner, and is whitish on the under 

 side of its branches. On the upper surface 

 the colouring is of a grey green. The general 

 growth is very irregular, and the plant as a 

 whole presents a wrinkled appearance. The 

 Evernia is not very commonly found in fruit, 

 and it is one of those lichens which rely to a 

 large extent upon the brood bodies which have 

 already been mentioned. 



The second group into which the lichens 

 may be divided are those which are generally 

 spoken of as "leaf-like." These creep along 

 the surface of the ground amongst the grass, or 

 spread over the trunks of trees. In their 

 general habit of growth some of these lichens 

 are not unlike that of the fiat-growing liver- 

 worts, although the bright greenness is lack- 

 ing. The most striking of these is certainly 



