A small amount of hay, including both stalks and leaves, 

 is cut into pieces ;ibout three inches long; four grafts of 

 this material is then olaced in a large beaker. To this 

 is added 0.2 gram of dry bread crumbs and 500 cc of dist- 

 illed water. The material is boiled for a few minutes, 

 and then poured into flat dishes to a depth of 1 to 2 cms. 

 The dishes are covered to keep out dust, and if water 

 evaporates from them it can be replaced by distilled water. 

 After the infusion has cooled, several pipettes full of 

 fluid are added from a culture which contains healthy 

 araebas, or from a pond or stream where amebas are found. 

 In doing this, care is taken to av-^id taking up any of 

 the sediment, for it is the sediment rather than the 

 super-natant fluid which is apt to contain enemies to 

 Ameba. This in^oculation may be repeated, and in the course 

 of two weeks the culture becomes cloudy .vith bacteria, 

 zoogloea, and small ciliates and flagellates: the food of 

 Ameba. A small dish of the culture fluid is now seeded 

 with amebas, being careful to avoid large organisms such 

 as Crustacea and worms. If living amebas are not present 

 a week later, more of the fluid containing amebas should 

 be added. This culture is used to innoculate the rest of 

 the infusion. The addition of a little hay occasionally 

 will keep the amebas present in great numbers. The room 

 should not be allowed to become very hot or very cold. 



(23) 



