210 Proceedings of the Royal Physical Society. 
600—but from 75 to 100 in the cysts where they could be counted in the 
sections. 
There seems to be no strict order for their formation—many are already 
free in the central portion, while near the margin some are not yet cut off 
(Pl. VII. Fig. 8 sa’). In other specimens (cf. Fig. 9) the central portion still 
contains protoplasm not yet apportioned to its nuclei. 
A young amoeba (Fig. 9a) from the cyst, a section of which is shown in 
Fig. 9, is drawn to a larger scale, together with one of the secondary nuclei, 
7a from Fig. 7, to the same scale. 
Until A. profeus can be induced to encyst in pure cultures without 
débris, the question of the young amoeb freed from the cyst must remain 
an open one, as amoeboid organisms of similar appearance turn up in any 
culture in which plant détritus is present, since material of this nature is 
always liable to contain organisms which have an amoeboid phase in their 
life-history—to say nothing of the great variety of small amoebe which 
live and multiply in such cultures. 
However, time after time, I have found free among the ripe cysts, young 
amoebze possessing blunt pseudopodia and a vesicular nucleus similar to 
that possessed by the amoebee just being liberated from the cyst (cf. Fig. 9a). 
These increased in size, too, for some days, but I was unable to keep them 
alive, under artificial conditions, for the length of time necessary to prove 
beyond a doubt that they were true A. proteus, and from that confidently to 
state that they originated from the cysts with which they were found. 
There are four points which Scheel puts forward as the conclusions to 
be drawn from his investigation. A statement of these, together with the 
results here obtained, will show in what the cysts described by him agree, 
and in what they differ, from those observed by myself. 
In size, outward appearance—except for the grouped cysts—and length 
of encysting period, 2} to 3 months, the two types are practically identical, 
but they differ upon the very important point of the behaviour of the nucleus. 
The four points referred to are as follows :— 
1. Bei Amoeba proteus tritt ausser der gewohnlichen Zweiteilung zu 
gewissen Zeiten ein multipler Vermehrungsprocess auf, welcher sich innerhalb 
einer vom Tier selbst ausgeschiedenen Hiill abspielt. 
2. Der Nucleus der encystierten Amébe zerfiallt durch successive direkte 
Teilung in eine grosse Anzahl von Tochterkernen, Enkelkernen usw. 
3. Der Amobenkorper zerfillt, wenn die Zahl der Kerne auf 500-600 
gestiegen ist, in ebenso viele sich gegeneinander abgrenzende Tochter- 
individuen, welche durch Zerfall der Hiille frei werden, 
