244 HANDBOOK OF NATURE STUDY 



which resemble each other. These kinds produce the dark, 

 spore-bearing heads in early summer. The spores develop 

 in a manner similar to those of the ferns. 



You will find horsetails common on moist meadows and 

 in shallow water; some also grow in rather dry soil, into 

 which they penetrate to a great depth. 



All ferns and horsetails in the temperate zones are small 

 plants and are of little importance in nature; but in a 

 former period of the earth's history, when the coal now 

 mined in the coal beds was deposited, vast marshy forests, 

 as large as our present prairies, extended over parts of this 

 continent and Europe. These forests consisted largely of 

 plants which in structure closely resembled our present 

 ferns and horsetails, but were of gigantic tree-like size. 



However strange arid beautiful these' forests and their 

 foliage must have been, they lacked nearly all of the cheer- 

 ful change and manifold life of modern woods. No autumn 

 ever lavished its glowing colors on them ; for many centu- 

 ries they stood in the same monotonous green ; no flowers 

 and butterflies enlivened mossy knolls ; no birds ever perched 

 and sang on the grand fronds. 



51. Mosses and Lichens. 



MATERIAL : The species illustrated, or any species that can be 

 found ; lichens gathered on the ground, on stones, and on the bark 

 of trees ; dried tufts of mosses and patches of lichens should be 

 moistened in presence of the children, to show how quickly moisture 

 revives the shrivelled plants, and how much moisture the mosses can 

 absorb ; pieces of wet and of dried peat. 



To give the life history of any moss in detail would not 

 be within the scope of this book. Suffice it to say that 

 the little capsules, which may be found on mosses at almost 

 any time, are the spore cases, and contain green or brown 

 spores. If the spores are shed on moist ground, they de- 

 velop a growth of green threads, and from these green 



