VITAL STAINING OF AMCEBOCYTE TISSUE. 



(corresponding to a n/iooo HC1 solution). While the tubes, 

 which contained the originally alkaline and neutral solutions, 

 were faintly stained, the acid solution showed the deepest stain. 

 In this case the destruction of a certain number of eggs caused by 

 the procedure used may possibly have complicated the result. 



Eggs heated to 50 or 100 for ten minutes and stained with 

 neutral red, gave off the stain even in a neutral solution of sodium 

 chloride. The effect of acid and alkali on the extraction could 

 therefore not be determined in this case. 



Corresponding experiments with eggs stained with eosin could 

 not be carried out because unheated starfish eggs do not stain 

 with eosin, and while eggs, heated to 75, take on a pink stain 

 with eosin, the quantity of stain taken up by the eggs is not 

 sufficiently great to make possible comparisons of the extractive 

 power of acid and alkaline solutions. 



Extraction of Stain from Stained Filter Paper. 



If filter paper is stained with neutral red, it behaves towards 

 extraction like amcebocyte tissue. For the purpose of extraction 

 the same solutions \vere used as in the case of amcebocyte tissue. 

 The stain is readily given off in an acid, but not in an alkaline or 

 neutral solution. 



Filter paper stained with eosin gives off the stain readily to an 

 alkaline solution, but only a very small amount is extracted by a 

 neutral and none by an acid solution. In other experiments 

 filter paper was stained with trypanblue and subsequently washed 

 in running water for one hour, then shaken with isotonic solutions 

 of n/iooo, w/5OO and 11/250 HC1 and NaOH as well as with a 

 solution of n/2 NaCl. Small particles of filter paper were 

 suspended in these various fluids. In accordance with the acid 

 character of trypanblue strong alkali extracted the stain, but 

 acid, neutral or weaker alkaline solutions did not. 



DISCUSSION 



i. The granules of amcebocytes stain readily with neutral red. 

 However, this is only a temporary effect ; very soon the granules 

 begin to give off the stain and this loss is almost complete within 

 the course of one or two days. The time at which this change 

 occurs varies somewhat, in some cells it takes place much earlier 



