244 M - R - LEWIS - 



normal cells. Gradually the pink color became deeper in tone 

 until it attained a pale port-wine color. Within a few seconds 

 the color disappeared from the central region of the cell and a 

 large, round port-wine-colored bleb appeared at one side of the 

 cell. Practically no change was observed in the structure of 

 the cell during the disappearance of the stain and the formation 

 of the bleb. Many of these blebs appeared scattered over the 

 membrane, especially in the region adjoining the explanted piece. 

 The color remained in them for about twenty minutes and then 

 faded out, leaving the blebs rather undefined and difficult to 

 distinguish. In some of the more peripheral cells of the mem- 

 brane the port-wine color remained diffuse in the cytoplasm of 

 the central portion for some time and then faded out without 

 forming blebs. The mesenchyme cells which had migrated out 

 on the cover-slip, away from the membrane, seldom formed blebs. 



3. Cell Processes. The processes of the cells formed the region 

 where the appearance of the port-wine color could be observed 

 most clearly. The large fan-like processes referred to above 

 exhibited lighter and darker areas where the cytoplasm varied 

 either in density or in thickness. After exposure to iodine some 

 of the lighter regions became pink. Later these turned into 

 distinct port-wine-colored areas in the yellow cytoplasm. A few 

 of the processes did not exhibit these stained areas at all; in 

 others some of the areas remained quite pale in color. This 

 phenomenon did not continue for longer than half an hour; at 

 the end of this time the color had faded and that area of the 

 process was slightly shrunken. 



When a drop of saliva was placed upon a culture which was 

 later exposed to iodine vapor the port-wine color was not found 

 in the cells. Death of the cell also prevented its appearance. 

 No granules having the characteristic glycogen color were seen 

 in any of the cultures. Neither the mitochondria nor any other 

 granules were concerned in the formation of the port-wine-colored 

 areas. It seemed as though the material which exhibited the 

 typical port-wine color was diffuse throughout certain parts of 

 the cytoplasm and became more definitely localized during the 

 death of the cell, w r hich occurred coincidentally with the iodine 



