THE LEISHMANIA OF ITAEIAN KALA-AZAli. 
365 
by Rosenbusch and some other authors, and I believe that I can 
exclude completely this type of the process of division in the 
case of Leishmania in the flagellated Leptomonas form. In 
this case there is a process of mitosis without formation of an 
achromatinic spindle giving rise to two daughter-cells 
exactly equal. I wished, however, to reproduce in the in- 
teresting figures 44, 45 and 46 some nuclei which present 
exactly the phenomena described recently by Horta and 
Machado (15) in Trypanosoma chagasi n. sp., a trypano- 
some of fishes in Brazil, and interpreted, I believe, erroneously 
as a complete process of heteropolar division. In support of 
my judgment there is also the fact that the authors cited have 
never seen two distinct nuclei arise from the supposed 
division, or subsequent fission of the protoplasmic body of the 
parasite ; just as I have never found this to occur in the 
Leishman ia. 
I believe rather that we are dealing simply with a reduction 
of nuclear chromatin, with no direct relation to the process 
of multiplication. Without wishing to suggest phenomena 
of maturation in relation with a hypothetical sexual 
differentiation, I am persuaded that these facts of nuclear 
reduction (since it is a question without doubt of a reduction 
of chromatin) are to be placed rather in the group of 
phenomena which Richard Hertwig terms Kernplasma- 
Relation ” (14). 
Having studied the process of division in many pre- 
parations, it has never happened to me to come across forms 
which would suggest that the kinetonucleus performs the 
function of a centrosome in the division of the principal 
nucleus, a function ascribed to it by Moore and Breinl, 
on which ground they have named the kinetonucleus the 
“ extra-nuclear centrosome.” The nuclear structure and the 
mode of division of the motor nucleus are sufficient to exclude 
such an interpretation, but it should also be recognised, from 
the examination of the preparations, that the division of the 
trophonucleus and that of the kinetonucleus appear up to a 
certain point to be independent the one of the other, so much 
