Plant Life ^ 



plants. If the sponge is set in a warm place, the moisture 

 causes them to grow rapidly. The growth changes a part of 

 the starch of the flour into alcohol and carbonic acid gas 

 which, rising in bubbles, makes the bread light. A sudden 

 chill prevents their growth, and the bread is heavy. Some 



germs are necessary to cause milk 

 to become sour. Flies are great 

 scavengers, eating from the walls 

 germs that might cause sickness. 

 They are not at all particular 

 about their food, and the day often 

 comes when the fly dines upon one 

 germ too many. It grows and 

 multiplies rapidly, and before the 

 day is over it completely fills the 

 fly and sends out little sticky 

 threads, which fasten it to the wall 

 or window. You may often see 

 them in wet weather. Upon these 

 threads little bodies— spores— are 

 borne, which blow about to tempt 

 other unwary flies. Some serve 

 locusts and grasshoppers in a 

 similar manner. It would be a 

 good way of getting rid of these 



Fig. 2.— Fungus-filaments from a 

 rotten potato. (From Thome and 

 Bennett's "Structural and Physio- 

 logical Botany.") 



f^-- ^■~I}^ '"'"^^ W mould, 

 (trom Thome and Bennett's 

 Structural and Physioloi^ical 

 Botany. ) 



plagues were it not that, for these spores to multiply rapidly, 

 moisture is necessary, and the locusts are not particular to' 

 time their visits to our gardens during the wet seasons. 



Lichens grow on rocks, where they look like splashes of 



