16 TALKS AFIELD. 



They all agree, however, in possessing the 

 one important power of assimilating, of ob- 

 taining their living from the inorganic mat- 

 ters which are contained in water, and they 

 therefore necessarily contain leaf-green or 

 other equivalent coloring matters. In the 

 power of assimilating they differ essentially 

 from all fungi. 



Peculiar to fresh water are the Desmids, a 

 few species of which are highly magnified 

 in Fig. 17. These microscopic 

 plants are composed of one cell, 

 and are bright green in color. On 

 account of their spontaneous move- 

 -^.IZ/ ments they were long regarded as 

 "Tx animals, but their methods of re- 

 Fig. 17. production class them with plants. 

 The power of moving from one place to 

 another is not now regarded as at all in- 

 compatible with the idea of a plant. The 

 desmids, as well as many other of the 

 lower plants, have two kinds of reproduc- 

 tion : one is a dividing of the plant into two, 

 and the other is a reproduction by means of 

 spores. 



The Diatoms are much like the desmids, 

 and for a long time they also were supposed 

 to be animals. From the desmids they dif- 



