84 PROTISTS AND DISEASE 



in five stages at b. The parasite's nucleus is at first a 

 " single chromatic globule lying free in the mass of the 

 cytoplasm." A nuclear space soon forms, c and d. Later 

 the nucleolus becomes the most prominent feature of the 

 nucleus, as at /, and from it strands of linin stretch to the 

 nuclear membrane. 



In the parasite's cytoplasm are numerous chromatic 

 granules ; a feature which becomes more prominent later. 

 Continuous with the nucleus, is a mass of linin fringed with 

 points of chromatin (the " amoeboid body " of Percival) ; 

 the chromidial granules in the cytoplasm are now more 

 numerous and the parasite has secreted a capsule upon 

 which matter from the remains of the host-cell is being 

 deposited, g. 



The Generative Chromidium. The chromidial granules 

 arise, Dr. Curtis states, by some six or seven intermittent 

 discharges from the nucleolus. They first accumulate in 

 estricted equidistant areas, Fig. 19, P, but afterwards 

 completely replace the cytoplasm, the remains of the nucleolus 

 then seems to be of no active service. The chromidial 

 sporangium is thus established. The granules of the 

 chromidium at first stain uniformly with iron-haematoxylin 

 and hence, as is explained below, the chromidium is at 

 first in the plasson state. The granules are the nodal 

 points of a fine reticulum and they soon show central chro- 

 matin granules with a clear space around them, and outside 

 a lightly staining zone, Fig. 22, h. 



