104 



THE SCIENCE OF LIFE. 



office seems to be to break down and to restore to the 

 inorganic world the effete formed material of animal 

 and vegetable life. Mushrooms, Puff-balls, Molds, and 

 the Rust of grain are examples of Fungi. 



8. The simplest forms of Fungi resemble Protophytes, 

 except in the absence of chlorophyll, either green or red. 

 Recent investigations have indicated that those which 

 seem most simple are but imperfectly developed states 

 of other species. The Torula cerevisicz, or yeast-plant, 

 which is the cause of fermentation in solutions of sugar, 



FIG. 38. Appearances presented by Bacteria under the microscope. At c, are iso- 

 lated Bacteria ; at d, they are arranged round a center ; while at a they appear in long 

 strings ; at e is observed a solitary torula. All highly magnified. 



and Bacteria (Fig. 38) of various forms, which cause pu- 

 trefaction in animal substances, appear to be varieties, or 

 stages, in the development of some of the u molds," or 

 microscopic fungi, many of which are capable of poly- 

 morphism, or the assumption of many forms. In some 

 kinds of fungi the bioplasm shows amceboid movements, 

 having a great resemblance to some of the lower forms 

 of animal life. 



9. Fungi are cellular organisms of variable consistence. 

 They exhibit two well-defined structures, a mycelium, or 

 spawn, (Gr. myces, a fungus,) formed of filaments some- 



