268 THE STORY OF PLANT LIFE 



tion is eminently successful. But, as has been seen 

 in other cases, Nature makes wise provision for 

 the perpetuation of species, and seldom errs. 



The achenes are dispersed by the agency of water. 

 Many must fall near the plant and germinate in the 

 muddy bottom of lake, ditch, or stream. 



Hornwort and Hornweed seem to be the only 

 popular names for these interesting plants. 



Ceratophyllum demersum. — Fig. 74 gives a good 

 idea of the habit of the plant, the slender stem, whorls oj 

 linear leaves, and the long internodes of the main stem. 



74. The Pine Group. 



The Pines which belong to the Order Coniferae, 

 including the Scotch Fir and the Yew, are not 

 described in this volume, since they are members of 

 the sub-class Gymnospermae. 



