314 
MAYNARD M. METCALF 
Amoebae are bred in pare cultures on agar plates, gemmulation 
occurs only in individuals thac are encysted/- and in these cases 
the body of the Amoeba from which gemmules have been freed 
disintegrates. One sometimes sees in the aquaria similar disin- 
tegrated bodies within the cysts which contain gemmules, but 
more often the body of the Amoeba, whether in a cyst or not, does 
not immediately degenerate after freeing its gemmules. Its ulti- 
mate fate I do not know. 
The nuclear phenomena have not yet been satisfactorily 
worked out, and I reserve for a future communication their de- 
scription. I may, however, say that there is fragmentation of 
the nucleus in the parent Amoeba, and that each flagellogamete 
contains a single nucleus. 
At first sight it seems not improbable that these phenomena are 
to be interpreted as the growth and emergence of parasites from 
the Amoeba, but more careful oDser\^ation shows that this can- 
not well be. In the early stages of the internal phenomena, pre- 
ceding gemmulation, one sees in the body of the Amoeba many 
scattered refractive plastids not at all aggregated into groups 
(figs. 27, 28, 29, 30) . In other, evidently later, stages some of these 
plastids are found aggregated into groups surrounding small 
nuclei (fig. 31). Other, and evidently still later, stages show that 
these nuclei, each one with its surrounding plastids, have moved 
to the surface of the body and there protrude, as shown in figs. 
32, 34. Sometimes many refractive plastids are left in the body 
of the Amoeba after all its gemmules are freed. Often only very 
few plastids remain, sometimes none are seen. From their ar- 
rangement in the bod}' of the Amoeba, it is clear that the refrac- 
tive plastids are scattered through the protoplasm of the Amoeba 
itself and are not grouped in the bodies of any parasites within 
the body of the Amoeba. 
The fact that biflagellate forms of the Cercomonas type are a 
stage in the life history of Amoeba is of no Httle interest. It is 
in harmony with the increasing behef that the flagellate type is 
more primitive than the Amoeboid. 
^2 All the Amoebae on agar plate cultures encyst after a few days. 
