58 



The dwellers hi the soil 



round fat globules of the milk, but the bad milk con- 

 tains in addition some tiny creatures, looking like very 

 short pins, darting in and out among the fat globules. 

 These living things must have come from the unbaked 



Baked soil 



Untouclied jelly 



Unbaked soil 



Fig. 26. 

 Soils contain tiny things that grow on gelatine 



soil or they would have been present in both flasks : 

 they must also have been killed by baking in the oven. 

 Another experiment is easy but takes a little longer 

 to show. Mix two sheets of leaf gelatine with a quarter 



