THE STRUCTURE OF TRYPANOSOMA LEWISI. Hs 
become shrunk and deformed, often very greatly, and the 
stain is blotchy and irregular. That has been my experience 
in all cases with smears fixed in Flemming’s fluid, 
sublimate-acetic, Schaudinn’s fluid, Mann’s fluid, etc., stained 
with Giemsa’s stain, and mounted without drying in Canada- 
balsam or dried off. Preparations made in this manner are 
usually quite useless, while the companion slides, stained with 
ivon-heematoxylin and mounted in the ordinary way, are very 
good. 
The Romanowsky stain has the further advantage of being 
easy to apply and comparatively rapid in action. It is 
therefore the method of choice for workers to whom time, or 
laboratory equipment, are material considerations—that is to 
say, to those dealing in a limited time with large quantities 
of material, or working under disadvantages of installation, 
as in the tropics. Nevertheless I shall try to show that, as 
Schaudinn! has already stated clearly, the Romanowsky stain 
has some glaring defects in its action on minute structural 
details, and that some false conclusions and interpretations 
have been based upon its results. It is very important that 
its effects should be studied carefully and compared with 
those yielded by other methods, for only in this manner is it 
possible to eliminate errors and to discount false appearances 
produced by it, and to obtain, so to speak, a constant formula 
for estimating and interpreting the results of its use. 
The peculiarities of the Romanowsky method of staining, 
as regards its effects on minute structures, are at once apparent 
when trypanosomes stained by this method are compared with 
others, fixed in precisely the same manner, but stained with 
iron-hematoxylin. ‘I'he differences are very great, and often 
very puzzling ; compare, for example, fig. 73, and figs. 14, 15; 
figs. 80, 81, and fig. 39; figs. 62, 63, and figs. 10, 11. To 
begin with the nuclear structures, the kinetonucleus appears 
1 “Nur ist sie (die Romanowsky’sche Farbung) mit Vorsicht zu 
benutzen, weil sie oft iiberfarbt und Strukturen vortauscht, die garnicht 
vorhanden sind. Ohne Kontrolle durch Haimatoxylin darf man keine 
Schlisse iiber Kernstrukturen bloss nach Romanowsky-Priparaten 
ziehen.”’ Schaudinn (1902), p. 191. 
