HOW THE TEST IS MADE 27 



(4) Exactly I cc. (i thimbleful) of this mix- 

 ture of milk and water is drawn out of the dilu- 

 tion-bottle by another glass tube and discharged 



DISCHARGING THE DILUTED MILK INTO A STERILE 

 GLASS DISH 



onto a flat glass dish having a cover. This dish 

 has also been sterilized. 



(5) Into the dish is then poured an exceedingly 

 stiff jelly made from a Japanese sea- weed called 

 agar. The jelly contains a little beef tea to 

 furnish food for the bacteria. When spread out 

 on the glass dish it hardens and all of the bac- 

 teria in the milk are glued fast. 



