THE LEISHMANIA OE ITALIAN KALA-AZAR. 
367 
fixation, especially with liquids containing osniic acid (osinic 
acid and Schaudiim’s fluid, Flemming’s and Hermann’s 
fluids), I have observed the presence in the space between the 
trophonucleus and kinetonucleus and very close to the latter 
of a corpuscle with contours not very sharply defined, for 
the most part rounded and without an internal structure, and 
stained more feebly than the unclear karyosome (see figs. 36, 
37, 21). In preparations fixed with osmic acid and Schau- 
diun’s fluid I have demonstrated fairly frequently a filament 
which, starting from the posterior pole of the parasite, 
traverses the body in a spiral and ends near the motor 
nucleus, in some cases in the body just mentioned, which in 
my opinion can be identified with that described by 
Novy (19) and by Sangiorgi (24) in trypanosomes. 
I have been led to these investigations above all by the 
very important works of Grassi and of Foa on the structure 
of the Protozoa parasitic in Termites, studies which have 
opened an horizon of research with regard to the motor 
apparatus of flagellate Protozoa. 1 do not know whether 
the various parts described in the Leishmanias as rhizoplast 
and kinetonucleus can be considered analogous to the org-a- 
nellgs described by Grassi and Foa, and named by Janicki tlie 
“ parabasal apparatus.” It may be that the ill-defined body 
situated near the kinetonucleus can be compared to the 
parabasal body. But after the e.xamination of many pre- 
parations with more or less effective methods of staining, I 
am certainly inclined at present to consider the spiral fila- 
ments demonstrated by me after osmic fixation rather as 
folds of the ectoplasm, artificial products of the preparation, 
than as true and proper structural elements. 
I have not omitted to undertake repeatedly examinations 
in the fresh state in physiological salt solution, and also in the 
.‘same liquid containing a very Aveak solution of picric acid, so 
dilute as to permit the flagellates to continue living for a 
certain time. The Leishmanias then show exactly the same 
form as in the stained preparations when the fixation has not 
been preceded by desiccation ; there is perhaps a still greater 
