Ihe amebas were transferred to different media by- 

 means of a fine glass c-^pillary pipette, the sharp end 

 of which had been made smooth by passing thru a flame. 

 In most of the experiments the animals were kept in drops 

 of fluid upon slides with a depression at each end- The 

 slides were kept in a moist chamber in a room whose temp- 

 erature did not vary greatly from 20 °C. For cutting the 

 amebas in half, or cutting the nucleus away from the rest 

 of the cell, a fine glass needle was dravm off at a slight 

 angle from the end of a glass rod. The cells were divided 

 under a binocular microscope. 



dince the animals would not live long in the tap 

 water '^f this city, a search was made at the outset for 

 a solution in which they could be kept in healthy, active 

 condition. Ten amehas were removed from a culture, freed 

 from food material and debris, and transferred to the solu- 

 tion to be tested. Each day they were examined and trans- 

 ferred to a fresh solution, the experiment being continued 

 until all of the animals were dead. It appeared at first 

 that distilled water was the most satisfactory medium 

 that could be obtained. Thus ten amebas lived (without 

 food) for an average of 13.2 days in distilled water, 

 whereas animals kept in tap water, for example, soon assum- 

 ed an abnormal appearance, and could seldom be kept alive 

 longer than one v/eek. But it was later discovered that 



(24) 



