THE HA E MO FLA CELL A TES 



221 



may occasionally be met with in combination in any given abnormal 

 form. (a) Chromatolysis. Here there is either a more or less 

 complete loss by the nucleus (usually the trophonucleus) of its 

 chromatic constituents, which pass out into the cytoplasm leaving 

 only a faintly staining plastinoid basis (Fig. 15, A) ; or else direct 

 fragmentation of the nucleus occurs (F-j). 1 (b) Vacuolisation. The 

 frequent presence of a vacuole in many Trypanosomes, which is 



A. 



FIG. 16. 



Involution and degeneration forms (continued). A-C, T. bntcii, after Br. and PI. ; D-G, T. 

 iiomiiiense, after Castellani ; H, T, briicii, after Martini ; J, K, T. equinum, after Voges ; L, T. 

 brucii, agglomeration-cluster, commencing to form a plasmodium, after I3r. and PI. 



probably to be regarded as a normal cell-organella, has been men- 

 tioned above. The first indication of abnormality in this direction is 

 perhaps afforded when the vacuole increases very greatly in size (Figs. 



15, E ; 16, E). Other, irregular ones may appear in the cytoplasm, 

 when the involution becomes pronounced in character (Figs. 15, C; 



16, G). (c) Change of form. This is, from the weird forms often 

 resulting, the most obvious line of involution. Alteration in shape is 

 generally accompanied by an increasing loss of mobility. In the 



1 In certain of these cases it is possible that something in the nature of chrom- 

 idial formation may be going on, leading to nuclear readjustment. 



