792 E. A. MINCHIN. 
various ways. I do not know whether my failure to find 
them is due to the minuteness of the object, or to my not 
having hit off just the right degree of extraction of the iron- 
hematoxylin stain. The trypanosomes in which I have seen 
myonemes have been very large species, and it is possible 
that in T. lewisi the myonemes are too minute to be resolved 
with the magnification used. On the other hand, myonemes 
appear to give up the stain very readily, while if over-stained 
they are obscured by the darkness of the preparation. There 
can be hardly any doubt that these active flexible organisms 
must possess a contractile apparatus which suitable methods 
of technique or optics would reveal. 
(3) The Cytoplasm. 
In the thickest part of the body, that is to say, in the inter- 
nuclear region and immediately in front of the trophonucleus, 
the cytoplasm shows commonly in preparations two distinct 
regions, a peripheral zone, situated immediately below the 
periplast, and an axial portion. 
The peripheral zone is usually seen in the ordinary 
Romanowsky preparations as a more or less distinct border 
marked off by its red tint from the axial bluish region (figs. 
60, 61). When the stain is extracted, however, the peripheral 
zone becomes clear and apparently empty, leaving the peri- 
plast-line standing out in the manner already described (figs. 
62-69). It is quite evident, from a comparison of different 
specimens, especially as regards breadth, that the appearance 
of the periplast-line is really due to the clearing up of the 
region immediately below the periplast and not to a dilatation 
of the periplast, or artificial raising up of it from the body. 
The question is, How is the clearing up of the region under 
the periplast effected ? Is it a clear zone of protoplasm which 
takes the red stain, and from which the stain is extracted, or 
is it really an empty space in which the stain is deposited 
and from which it is dissolved out again? And if it is an 
empty space is it one naturally present, filled only with fluid 
in the living condition, or isit produced artificially by shrink- 
