The Cyst of Amoeba proteus. 211 
4. Kin Flagellatenstadium tritt bei Amoeba proteus nicht auf. Die 
Sprosslinge gehen direkt in das Amébenstadium tber. 
That A. proteus divides by the ordinary twofold division is now an 
established fact; but that the multi-nucleated form, which itself divides 
by direct division—and probably also undergoes fragmentation—is identical 
with the uninucleate form of A. proteus still remains to be demonstrated. 
Scheel figures the nuclei in the cyst in various stages of division—and 
by this shows that the nucleus of the encysted amoeba does not break down, 
as stated in this paper, but divides throughout by direct division. Again, as 
I have mentioned, the number of small amoeba produced in the cysts 
observed by myself is not more than one-fifth of the number shown 
by him. 
Finally Scheel’s observation that Amoeba proteus passes through .no 
flagellate phase in its life-history agrees with the conclusions reached 
in this short paper. 
That there may be two types of cysts in A. proteus, as Popoff! has 
shown to be the case for A. minuta, seems quite possible and not at all 
improbable to one who has studied the various amoeb which lay claim to 
the name A. proteus at the present day, but we have still to discover (a) 
the second cyst similar to Scheel’s if it exists, and (>) the stages connecting 
it to the type of cyst described in this paper. 
This work has been carried on partly at the Zoological Department, 
Glasgow University, under the supervision of Professor Graham Kerr, and 
partly at the College of Notre Dame, Dowanhill. I am much indebted 
to former lecturers in Protozoology at the University —Mr C. H. Martin 
and Mr J. Dunkerly—for their kind criticism and encouragement throughout. 
1 Loc, crt. 
[DESCRIPTION OF FIGURES. 
