APPENDIX 689 



100 cover slips No. 2. \ lb. rochelle salts. 



1 mortar and pestle. 6 oz. glycerine. 



Fehling or Benedict solution. 



The following items may be made or obtained locally : 



Pocket garden. 



Ventilation box. 



Foods containing proteins and oils. 



Soil : sand, clay, gravel, loam, humus. 



Seeds : peas, beans, radish, corn. 



Starch, sugar. 



The agar or gelatine cultures in Petri dishes may be obtained from the local 

 board of health or from any good druggist. These cultures are not difficult 

 to make, but take a number of hours of consecutive work to prepare. 



Prepakation of Culture of Protozoa 



If it is impossible to buy cultures of Paramecia for study, they can be pre- 

 pared in the school laboratory. Fill a sterilized battery jar about half full of 

 water and add a small handful of hay stems cut in short lengths. Keep the 

 jar in a fairly light place. In a few days a scum will form on the surface of the 

 water, in which bacteria will be found. Later protozoans, including Paramecia, 

 will appear. 



