HIDDEN MARRIAGES 



533 



when diseased. Many of the Lichens have long been extensively used in 

 the art of dyeing. The Reindeer Moss already referred to is of the utmost 

 value to the wandering Laplander, who feeds his domestic herds upon it 

 during the winter. The Reindeer are said to know where it is growing 

 under the snow, which they scrape away with their antlers. The Icelander 

 makes similar use, not only for his cattle, but for himself also, of another 

 Lichen, the Iceland Moss (Cetrarla islandica), which at one time had a great 



Photo by] 



[E. Step. 



FIG. 677. DOG LICHEN (Peltigera canwa). 



One of the largest of the Lichens. It grows upon the ground and resembles a Liverwort on a large scale. The 

 fruits of a pale-brown colour, with incurved margins, spring from the edge of the thallus. 



vogue in this country as a food for invalids, and still retains a place in the 

 British Pharmacopoeia. 



The compound body of the Lichen is known as a thallus. Although 

 subject to great variation of form all the kinds may be separated into two 

 groups those that lie flat and spread upon the surface they grow upon, and 

 those that branch and grow in a vertical direction. The first kind are 

 known as foliaceous Lichens, the second kind as fruticulose Lichens. The 

 Dog Lichen is an example of the foliaceous class, the Reindeer Moss may 

 stand as representative of the fruticulose class. There is a subdivision of 



