A clear, straw-colored fluid, with a bitter-3weet taste. 

 The reactions for barium, calcium, iron, reduced sulphur, 



and tryptophane were negative; phosphate v/as present, and 



react f OK 

 the xantho-proteic -«^-r4- was positive. When exposed to the 



air, bacttria develop^_^with remarkable rapidity. The solu- 

 tion v/as not toxic to amebas, even when evaporated to one 

 half the volume, but evaporation to one fifth the volume 

 resulted in a solution which was slightly toxic. 



This solution of ^.mino acids is lacking in glycine, 

 which is absent in casein, and in tryptophane and cystine, 

 which have been destroyed. 



In cultivating amebas in this solution, it was dif- 

 ficult to prevent the development of bacteria, but a meth- 

 od was devised which served to exclude them almost com- 

 pletely. The amebas were washed five to ten times in 

 sterile water, and the slides upon which they v/ere kept 

 were boiled. The culture solutions were kept in small 

 flasks fitted with capillary tubes. By inverting the 

 flask and warming with the hand, a few drops could be 

 placed upon the slide. After using, the flask was boiled 



The toxicity of amino acids observed by Burrows and 

 Neymann (1917) upon embryonic chicken cells was probably 

 due to the relatively concentrated solutions used. 



(39) 



