6 TALKS AFIELD. 



tain green or red coloring matters. Some 

 plants, however, of which mushrooms are 

 examples, live entirely upon organic matter 

 in something the same manner as animals 

 do ; they must therefore live upon decaying 

 substances, when they are known as sapro- 

 phytic plants, or uj^on live plants or ani- 

 mals, when they are known as parasitic. 



In a general way we may say that the 

 lowest class of i)lants are the Fungi. The 

 plants which are commonly included under 

 this term are exceedingly numerous, and 

 their individual characters are extremely va- 

 riable. Some of them are so small as to 

 be seen with difficulty through the best mi- 

 croscopes, while the largest are gi- 

 ant puff-balls which weigh many 

 pounds. The fungi all live upon 

 organic matter, — they are either 

 saprophytic or parasitic. Most of 

 them are grayish or neutral-tinted. 

 The lowest and the most minute 

 of all known organized structures 

 are the Bacteria. Under this de- 

 nomination are included great num- 

 bers of microscopic plants, which 

 ^'^" ^' are very imperfectly understood. 

 They are simple in structure, each Individ- 



