with the nucleus, we are removing no important organ of the 

 cell. The one disadvantage in the use of this fascinating 

 living cell is the difficulty of cultivating it. Like all 

 rhizopods amebas are difficult to raise, but many invest- 

 igators have succeeded in keeping healthy cultures in the 

 laboratory for years. 



In view of the difficulties which are so often met in 

 cultivating amebas, it may not be out of place to adi one 

 moi'e method to tliose which have been described for rearing 

 these valuable experimental animals. It is almost liter- 

 ally true that each investigator has a method of raising 

 amebas, but that no one can use it except himself. This is 

 not surprising when it is seen that "water" is employed 

 in making the cultures, with little regard for its purity. 

 kVhile amebas nay flourish in the "water" of one locality, 

 they may tiuickly die in the ^vater of another locality. 

 This difficulty was avoided by the use of distilled water. 

 The method which follows is based upon one which has been 

 employed by Miss Hyman of the University of Chicago- 



The prejudice of many biologists against the use of 

 distilled v/ater, and the prevalent notion that it is toxic 

 are not supported by experiments upon the toxicity of 

 distilled water. (Daniel . 19'-')' 



(22) 



