ANNALES DE L’INSTITUT PASTEUR 
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formation and extrusion of buds the amœbæ multiplied 
rapidly in the cultures. 
In preserved spécimens l lie body of the amœba was seen 
to contain a conspicuous principal nucléus (N, fig. 1), visible 
in lhe liying condition, and very numerous chromidial grains 
in the cyloplasm. In the process of binary fission, the apparent 
disappearance of the principal nucléus was due to ils dividing 
by mitosis, after which the cytoplasmic body divided also. In 
the process of bud-formation lhe principal nucléus took no part; 
the process began byasmall portion of lhe cytoplasm, contain- 
ing chromidia, becoming surrounded by a clear space with 
fluid contents and thu< eut off from the rest of the body (fig. 1, 
A, b), The corpuscle ihus defined grew in size, its chromidial 
grains increased in number, and some of them became clumped 
togetber at one spot (lig. 1, F, b). The entire corpuscle was 
extruded finally from the body of the amœba (fig. 1, C, I), E) 
as an amœbula wich contained a nucléus formed from the 
clump of chromidia. In some cases the nucléus was complelely 
formed before the bud was extruded (lig. 1, D, b)\ in other 
cases the bud might be set lVee with its nucléus scarcely 
advanced beyond the condition of a clump of chromidia 
(fig. 1, E, N). Several of tliese endogenous buds could be 
observed frequently in process of formation in one and the 
sa me amœba. 
If we now compare the process described by Fry and llanken 
in trypanosomes with that described in amœbæ by Liston and 
Martin, I think no one can fail to be struck by their essenlial 
similarity. The bud-formation in trypanosomes begins with 
extrusion of small chromatin-grains from the trophonucleus 
(lig. 2, À, chr.), grains which are proved, bot h by their origin 
and desliny, to be true chromidia. The chromidial masses 
can he seen in many <ases to be eut off from the cytoplasm of 
the parent by a clear space ; tliey travel to the surface <»f lhe 
body and are cast olf from it as a free bud, which grows in size 
and develops into a tiypano^ome (fig. 2, E-L). In the process 
of development the bud grows in size by increase of the chro- 
matin-grains (E) and formation of a cytoplasmic body (F) 
wliile at lhe saine time the différentiation of lhe chromai in- 
elements into trophonucleus and kinetonucleus becomes appa- 
