THE STRUCTURE OF TRYPANOSOMA LEWISI. 767 
preparations stained by this method, unless the contrary is 
stated. 
When used directly on the wet films both fixatives gave 
very similar results. ‘he trypanosomes are under-sized and 
deformed, appearing too short in proportion to their breadth, 
as if contracted in the longitudinal direction (figs. 36-38, 
40-44) ; their attitudes in the preparations look strained and 
unnatural, as if their end had not been a peaceful one. The 
amount of the deformation is distinctly greater after 
Hermann’s fluid than after Flemming’s, and with the latter 
re-agent 1t varies in different preparations. I am inclined to 
think that the amount of deformation is related in an inverse 
manner to the degree to which the films have lost moisture 
previous to fixation. However carefully and rapidly the 
preparation of the film be carried out, it is clear that a thin 
film of blood must lose a certain amount of moisture before it 
reaches the fixative. My impression is that the more the 
fiim dries before coming into the fixative, the less the 
trypanosomes undergo shrinkage and distortion of the 
body-form, 
As regards minuter details, the following points are to be 
noted: The body of the trypanosome does not show a peri- 
plast-line ; the nucleus has an appearance most characteristic 
of the effects of these fixatives ; 1t 1s surrounded by a clear 
space, often very distinct, but not sharply lmited (figs. 36-38, 
43, 44), which I regard as the result of shrinkage. In the 
nucleus the karyosome is very distinct, and frequently also 
other coarse chromatic granules are to be seen. A _ similar 
condition of the nucleus could be made out also in trypano- 
somes stained with all the other staining methods that were 
used, and must, therefore, be attributed to the action of the 
fixative. 
The kinetonucleus and blepharoplast appear normal after 
Flemming’s and Hermann’s fluids, but the flagellum often 
appears extremely crinkled, with sharp bends and angles, 
very different from the normal smooth undulating curves ; its 
appearance is strongly suggestive of longitudinal shrinkage. 
