CHAPTER IV. 



THE FUNGUS BODY OF HYPHAL ELEMENTS. 



Fungi. 



Fungi are plants without chlorophyll, whose body is gen- 

 erally made up of long filaments, either loosely or densely 

 interwoven and united. 



47. Origin. — As the bacteria, the smallest and simplest 

 plants, were derived from the lowest alga? by slow adaptation 

 to a different kind of food, so, at various points in the 

 ascending scale of algal life, certain algae have adapted them- 

 selves to the use of organic food which they could secure 

 ready-made. These, having no use for the chlorophyll and 

 chloroplasts, have gradually lost them. The adoption of the 

 habit has proved highly successful, both among the simple 

 bacteria and the more highly organized true fungi. The 

 ancestors of the present species were — how long ago no one 

 can say — probably at first chiefly, if not exclusively, aquatic. 

 Some, at the present time, have the same habit, growing in 

 infusions of organic matter. Others attach themselves to dead 

 or even living animals or plants in the water. The soil (con- 

 taining in its upper layers more or less organic matter from 

 the offal of plants and animals, or from their dead bodies) 

 and dead or living organisms furnish places of growth for a 

 great number of species which have adapted themselves to 

 other than aquatic life. 



48. Hyphae. — The filaments of which the fungus body is 



39 



