THE HAEMOFLAGELLATES 



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. bnicii, after Br. and PI. ; D-G, T, 

 gamtnense, after Castellani ; H, T. brueii, after Martini ; J, K, T. equinum, after Voges ; L, T. 

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



probably to be regarded as a normal cell-orgaiiella, 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. 



1 5, 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. 



