ACHROMASIA 55 



if a temperature of about 30 C. is maintained, which 

 may prevent the bulging of the cell-wall; but after 

 that time the cell will either burst and become 

 achromatic, or become achromatic without bursting 

 (fig. 14). In either case achromasia, or loss of stain 

 from the cell, invariably occurs. If the temperature 

 is low (say that of the room) the cell will probably 

 burst and its granules will be scattered about on the 

 surface of the jelly. Now, when a cell bursts on a jelly 

 which contains salts such as the one with which we 

 are supposed to be experimenting there is another 

 rule to which there is no exception, namely, that the 

 cell's nucleus loses its stain instantly. In a flash all 

 coloration has gone from it. But the granules may 

 remain stained for half an hour or more; and then 

 they also gradually lose their stain (fig. 15), and appear 

 slowly to vanish from the scene. The phenomenon 

 of achromasia always overtakes the cells sooner or 

 later. 



If the cell does not burst, the stain disappears, but 

 its disappearance is much slower. This is a pretty 

 phenomenon to watch; but it requires a warm room or 

 warm stage. Suppose we are watching a cell which 

 is dead, having its nucleus and granules stained bright 

 scarlet. The stain gets a deeper colour, and one 

 wonders how deep a shade it will attain to. Suddenly 

 the staining seems to stop, and the depth of colour .may 

 remain the same for a quarter of an hour or so. Then, 

 almost imperceptibly at first, the colour becomes paler, 

 and with an accelerating speed the colour fades away 

 from the lobes of the nucleus, until that structure 



