THE LEISHxMANrA OF ITALIAN KALA-AZAE. 
363 
which begins to protrude from the anterior pole of the 
parasite and subsequently grows continually in length 
(figs. 4 , 5 , 9 , 10). At the same time or immediately after- 
wards the division of the karyosome takes place. 
It should be noted at this point that I have never found 
true and proper figures of karyokinesis of the kinetonucleus 
with the formation of an achromatinic spindle. 
All these stages of division are, of course, only to be 
observed in preparations fixed by wet methods and suitably 
stained; dried preparations give only a very inexact and 
incomplete idea of the whole process (figs. 6 and 7). 
The successive stages of division of the kinetonucleus can 
be followed step by step in figs. 9-18 and 31-35. The 
karyosome becomes elongated and constricted in the middle, 
and the two halves which ai'e thus produced travel further 
and further apart, remaining connected by a very slender 
filament, which persists during the division of the tropho- 
nucleus; in this way a true centrodesmosis of the kineto- 
nucleus is formed. At this stage there exist already two 
rhizoplasts and two flagella, which usually become detached 
from the two halves, still connected, of the kaiyosome. 
Special interest attaches to the Leishmania represented 
in fig. 34; in this specimen the two flagella take origin from 
two granules situated outside the two halves of the karyo- 
some and respectively very close to each of them ; a very 
delicate achromatinic filament unites the two granules or 
blepharoplasts properly so-called, from which, as I have said, 
the flagella originate. This would prove that the blepharo- 
])lasts have the significance of centrioles of the motor nucleus, 
and that actually in an early period of the division they are 
found in the interior of the karyosome, at the point when the 
flagellum of the flagella already formed seem to take origin 
from the interior of the karyosome itself; subsequently, 
howevei’, the blepharoplasts regain their normal position in 
the sap-zone near the membrane. 
Tlie division of the principal nucleus follows a process 
perfectly analogous, and takes place in all its stages within the 
