212 Proceedings of the Royal Physical Society. 
DESCRIPTION OF FIGURES. 
All figures drawn with aid of an Abbe camera. 
Figures 1 and 2. Optical sections from life—Zeiss oc. 4, obj. D. 
Figures 3, 4, 5, 6, 7, 8,9. From stained sections 5 » in thickness—Zeiss oc. 2. 
Leitz oil immersion ;; inch. 
Figures 74,94. Zeiss oc. 12. Leitz oil immersion -; inch. 
The ages of the cyst stages figured from sections are approximately as follows, 
reckoning from time of encystment— 
Fig. 3 about 10 days. Fig. 7 about 6 weeks. 
” 4 ” 14 ” ” 8 ob) 8 ” 
Figs. 5and6 ,, 21 _,, 309) LO 
From Life. 
Fig. 1. An amoeba just rounded off in nest of débris 
$y 2b 9p * in completely formed cyst. 
From Sections. 
Fig. 3. Breaking down of nucleus. 
, 4. Passing of plastin? from nucleus (pl.). Shows 1st membranous wall (0). 
», 9. Chromidia throughout cytoplasm, Stain no longer held by nucleus. Wall (c) 
does not show in this cyst. 
, 6. Showing the remains or rather the degenerating matrix of the nucleus, and again 
the torn outer membrane. 
», 7. The appearance of the secondary nuclei. The outer walls are not shown in this 
section. 
5, 7A. Two of the secondary nuclei drawn to a larger scale, showing in one case the 
centriole, which may be seen occasionally in some of these small nuclei. 
, 8. The apportioning of the protoplasm to the secondary nuclei. Some amoebe 
not yet free at margin (sw’). 
, 9. The small amoebe being set free into the cyst cavity, but not yet to exterior. 
Some amoebre (sa’) not yet free in the central portion. 
, 9A. Small amoeba from another section of cyst 9 above, showing pseudopodia, 
nucleus (cf. 7A). 
Letter References. 
a. Outer wall of débris. 
b. Ist membranous wall. 
c 2nd membranous wall. 
12 Protoplasm of amoeba-body. 
N. Nucleus of encysted amoeba. 
n Secondary nucleus. 
ch. Chromidia. 
pl.  Plastin or plastin-chromatin complex. 
sa. Small amoebe product of encystment. 
sa’. . », not yet completely defined. 
Nm. Nuclear membrane. 
(Isswed separately, 15th September 1915.) 
