198 
protozoa or protophytes the trypanosomes belong. There seems, 
however, to be little doubt that much of our present ignorance and 
confusion concerning the morphology and the life cyde of the 
trypanosomes has been due largely to an accident of technique, due 
in fact to the circumstance that the presence of trypanosomes can ven- 
readily be demonstrated by drying and staining the blood in whidi 
they are contained. It has so happened that by this method in is 
various forms, not only is the presence of trypanosomes demonstrated, 
but the preparations produced in this way are often extremely sharp, 
and beautiful to look at. It has consequently been only after a 
prolonged investigation of the effects produced upon such organisms, 
and on other forms of cells, by the process of drying, and by a careful 
comparison of the results obtained by this and other methods of 
fixation, that it has begun to be realised that dried preparations of 
cells, except for the purposes of demonstrating the presence of 
parasites, are generally as misleading as they are beautiful. 
We have referred to this matter in our former papers, and we may 
say that all our further acquaintance with trypanosome morpholep' 
indicates clearly that the process of drying is entirely destructive of 
the finer cytological details, and consequently that it is altogether 
inapplicable to investigations wherein a true conception of the normal 
featuies of tiypanosomes, or indeed of any cells, is necessary I'' 
consequence of these considerations, we have entirely abandoned the 
use of dried preparations, and have relied here, as in our former 
work, upon modifications of the various methods of fixation in 
common use arnong Cytologists, together with such modifications of 
various staining methods as have been found necessary' durii^ 
e course of the work. The features of the developmental cycle or 
1 e istory of T. lewisi, although remarkable, in reality only assumf 
rue proportion when considered in conjunction with the facts 
relating to the development of other trypanosomes that have no«- 
been studied. 
For the sake of convenience, and for purposes of reference in 
subsequent portions of the present work, we shall in the first pW 
the ^ our observations upon the developmental cyde i" 
case o . gambiense and T. equiperdum. Before doing 
had'^tnT- to indicate the objects which we origina^'y 
lew in selecting the three forms, T. gambiense, T. equiperdn^ 
