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7. Touch the rim of a public drinking cup to the gelatin of 

 No. 7. Set it aside and observe it daily. 



8. Cause a house fly to walk across the gelatin of No. 8. 

 See that the legs of the fly touch the gelatin at several places. 

 Set it aside and observe it daily. 



9. Touch the gelatin of No. 9 with dust from the street or 

 roadway. Set it aside and observe it daily. 



10. Note. Eeserve the rest for second trials, if necessary. 

 The above cultures are known as inoculations, as they were 

 inoculated ; that is, germs were planted in a favorable growing 

 place. 



11. Tabulate your results as follows : 



Note. Each spot on the gelatin represents a colony of bac- 

 teria, or mold, which has developed from germs originally 

 placed there. 



Conclusions. 1. From what different sources may bacteria 

 enter the body ? 



2. Explain just how bacteria may enter the body from the 

 different sources enumerated in your last answer. Note. It 

 has been recently proved that cracked earthenware dishes, 



SHARPE S LAB. MAN. 



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