CHAPTER XIII. 

 MOSSES, FERNS, AND HORSETAILS. 



PROVIDING MATERIALS. 



Mosses and ferns can be obtained at any time of the year in green- 

 houses. The prothallia of ferns usually grow in great quantities in the 

 shady and moist soil beneath the benches. Mosses may also be found 

 in good condition in the shade and shelter of woods in early spring and 

 summer, and even in the winter season, in some localities. When 

 mosses and fern prothallia are found bearing antheridia and archegonia, 

 it is a good plan to lay in a supply in formalin or 70 % alcohol. Equi- 

 setums, or horsetails, should be gathered in fruiting condition in early 

 spring and summer, and preserved dry or in formalin. Some mosses, 

 ferns, and horsetails should be collected in the fruiting condition and 

 preserved dry for experiments with the spores. 



OBSERVATIONS. 



MOSSES. 



170. Examine mosses in their natural habitat. Separate 

 a single plant carefully from its associates and from the 

 substratum. What is the character of the members which 

 connect it to the substratum .' What is the nature of the 

 substratum ; is it moist or dry .' 



171. Examine mosses which are in fruit. The fruiting 

 stage will be recognized as the slender stem growing from 

 the apex of the leafy stem and terminating with a capsule 

 which bears the spores. Examine the spore capsules of 

 different ages. Notice how they normally break open. 

 Examine the opening with a lens, and shake out some of 

 the spores and examine them with a lens. 



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