288 Introduction to Botany. 



176. Dig up a clump of mosses in fruit, and place it in a 

 shallow dish containing sufficient water to keep the bottom 

 of the clump moist. Cover it with a bell jar, and after a 

 few hours remove the bell jar and observe the behavior of 

 the capsules as the atmosphere about them becomes less 

 humid. 



FERNS. 



177. Examine ferns in their natural habitat. Note ex- 

 posure to the sun, and the nature of the soil, whether it 

 is moist or dry. Dig up a plant and observe the character 

 of the underground parts. 



178. Examine the back of the leaves for the rounded or 

 linear clusters (son, singular sorus) of sporangia. Select 

 a portion of a leaf which shows by the brown color of the 

 sporangia that the spores are ripe, and place it under a 

 bell jar on a piece of moist white filter paper. After a few 

 hours remove the bell jar and examine the paper with a 

 lens to see whether the spores have become scattered. 

 Even old herbarium specimens might answer the purpose. 



179. Scatter spores over pieces of brick and keep moist 

 under a bell jar, as directed for the spores of mosses. After 

 a few weeks the spores should have germinated, and the 

 green bodies resulting, known as the prothallia, should be 

 examined under a microscope. How are they anchored to 

 the brick ? After a time archegonia and antheridia should 

 be observable on the under sides of the prothallia. Take 

 care of the experiment until young fern plants begin to 

 grow erect from the prothallia. 



HORSETAILS. 



1 80. Note the character of the habitat in which horse- 

 tails flourish. Dig up some of the plants and observe the 

 nature of the roots and the relation of the plants to each 



