362 
ARRIGO VISENTINI. 
In other cases the flagellum is united directly to the 
kinetouucleus, and in many cases (figs. 5 , 10-13, 26, 31) the 
impression is obtained that it arises directly from it. Then 
there is no basal granule in its usual position. The possibility 
cannot, of course, be excluded absolutely that in these cases 
the basal granule and point of origin of the flagellum are 
found in a slightly lower plane, behind the kai’yosome which 
lies over it, but the figures are very suggestive of the inter- 
pretation that the flagellum is really in continuity with the 
karyosome, within which in such cases the blepharoplast would 
also be found. Moreover, to the latter is attributed usually 
the significance of the centriole of the motor nucleus ; and 
the assumption that the blepharoplast is found in some cases 
in the interior of the karyosome explains also, as we shall see 
in the sequel, the behaviour of these various elements in the 
process of division. 
It is known that in Leishmania the process of division 
begins usually by that of the kinetonucleus ; nevertheless 
there are cases in which a precocious multiplication of the 
principal nucleus takes place, so that there may be in the 
same parasite two trophonuclei completely distinct and 
the first stages of division of the motor nucleus. In the 
kinetonucleus the process begins by the division of the ble- 
pharoplast, followed immediately by that of the flagellum; 
in this way are produced forms in which, as in figs. 7, 8, 16, 
18, there are two rhizoplasts which unite anteriorly, and 
which are continued by a single flagellum ; in these cases 
either there are already two basal granules in the sap-zone, 
or the doubled rhizoplast is continued into the interior of the 
karyosome, and this is almost the rule. 
The splitting of the flagellum proceeds rapidly, and from 
it results almost always a normal flagellum, and, near it and 
parallel to it, one much shorter (figs. 6, 9, 10, 11, 13, 14, 31, 
33, 34, 35), as is observed frequently also in trypanosomes. 
In most cases, howevei’, after the new rhizoplast has been 
formed, it detaches itself at its distal extremity from the 
other, and, when separated, gives origin to the new flagellum. 
