56 CELLULAR STAINING, DEATH, ACHROMASIA 



remains as unstained as it was when the cell first came 

 to rest on the jelly-film. After a few minutes the 

 granules slowly lose their stain also, until nothing seems 

 to remain. Ultimately the red cells disappear too (figs. 

 14, 15), and the field, which a short time previously was 

 dotted with red cells and stained leucocytes, now 

 becomes a blank, and a new-comer looking at the 

 specimen would hardly believe that there had ever 

 been any cells under view. The picture afforded by 

 the successive occurrence of the staining, death, and 

 onset of achromasia in the cells is well worth seeing. 

 First the slow diffusion of the stain into the cells, 

 staining first their granules and then their nuclei; 

 the gradual retraction of pseudopodia as the nuclei 

 stain, and then the bright scarlet coloration of the 

 nucleus itself as death occurs... After a pause the 

 gradual fading of the stain, first from the nucleus and 

 then from the granules, until at last nothing remains 

 visible of the leucocyte in the place it filled among 

 the neighbouring red cells. The whole phenomenon 

 reminds one of a lantern dissolving view the onset 

 of staining, its climax, and then its disappearance. 

 Achromasia invariably occurs after a time nothing 

 which we know of will prevent it; but heat greatly 

 accelerates its onset, and a ruptured cell always becomes 

 achromatic before a whole one. 



I do not propose here to give the details of ex- 

 periments which I made some years ago, to try to 

 investigate the nature of this phenomenon of achro- 

 masia; they will be found in a paper, ''On the Cause 

 of Achromasia," in The Lancet of January 23, 1909. 



