6 MABY JANE HOGUE 



blue, the granules a deep blue, and the cytoplasm blue. The 

 nuclear area around the karyosome remained clear and the 

 amoebae moved freely. Later they rounded up into blue balls 

 surrounded by a lighter blue ectoplasmic area. In this area the 

 nucleus was usually found away from the endoplasm. The 

 amoebae were dead. 



When the solution of methylene blue was diluted one-half, the 

 effect on the amoebae was the same, though the animals did not 

 die so quickly. When it was diluted one-fourth of the original 

 strength, it stained the amoebae the same as the original solution 

 had stained the tissue-culture cells. The cytoplasm was clear, 

 the nucleus unstained and invisible except as a clear area in the 

 endoplasm free from granules. Many of the granules were 

 colored blue, though not all took the stain. To this stain also 

 the amoeba cell is four times as sensitive as the tissue-culture cell. 



MITOCHONDRIA 



The amoebae were treated with janus black no. 2. A very 

 weak solution was used, as otherwise the amoebae would contract 

 and die without showing the mitochondria at all plainly, though 

 the nucleus stained well. 



When the amoebae stained slowly the mitochondria appeared 

 as small short rods, like bacilli, in among the neutral-red granules 

 (j5g. 2) . Some of the mitochondria were round, and frequently 

 after they had been stained for some time groups of three or four 

 small mitochondria would be found in among the larger ones 

 (fig. 3). No long branching mitochondria were found in the 

 amoebae, though they are very common in the fibroblasts. The 

 mitochondria retained the stain and were visible as long as the 

 amoebae were aUve. This stain seemed to have a stupefying 

 effect, as the amoebae died with their pseudopodia extended 

 instead of rolling up into balls. 



The mitochondria, when the amoeba is dying, have very 

 marked brownian movement. In the later stages of death the 

 mitochondria move out into the clear ectoplasm which before has 

 been free from granules of all kinds. This does not occur in the 

 tissue-culture cells, as I have already shown (Hogue, '19). 



