THE CHROMATIN MASSES OF PIROPLASMA BIGEMINUM. 305 



is rather less dense tliau the blepliaroplast. The loose 

 chromatiu varies somewhat in texture in different forms. 

 It often consists of relatively coarse, chromatic granules, 

 closely associated and touching each other, yet loosely 

 packed compared with the principal chromatin masses, and 

 staining less deeply than these; and this structure maybe 

 well seen under monochromatic light, after one has carefully 

 determined the loose chromatin area under white light. 



The foregoing description applies to the distribution and 

 structure of the chromatin masses as seen in the most 

 commonly-occurring parasites (about one-fifth of the whole). 



Another fairly common form of distribution of the chro- 

 matin in pyriform parasites may be termed the " polar " 

 distribution (text-figs. 5, G, 7, and 8). In these forms there 

 is a large nucleus near the blunt end of the parasite, and a 

 small mass of chromatin — the so-called blepliaroplast — at some 

 distance from it, sometimes near the apical end (text-figs. 

 5, 6, 7). The position of the nucleus in these parasites 

 corresponds with that often noted in the past before the 

 blepliaroplast Avas observed. Occasionally, however, the 

 relative position of these two nuclear masses may be reversed 

 (text-figs. 11 part,^ 14 part), and the larger chromatin mass 

 then appears near the pointed end. 



The nucleus and so-called blepliaroplast occasionally occur 

 close together (text-figs. 10, 9 part, 18 part). 



Forms in which the chromatin masses appear much alike, 

 both as regard size and density, are sometimes found (text- 

 tigs. 13, 15). 



One of the parasites represented in text-fig. 18 has much 

 chromatin of varying density, along one side (cf. Koch [1^ 

 taf. 1, figs. 1, 2, 4]). 



Other types, such as are drawn in text-figs. 9, 12, and 16, 

 are rare, especially the latter, where the parasites possessed 

 only a paucity of chromatin. 



Smaller, and presumably younger, iutra-corpuscular pairs 



1 " Part " here refers to the fact that only one member of the pair of 

 parasites shows the particular feature. 



