STUDY OF PATHOGENIC AMCEBAl FROM BOMBAY. 123 
granules forming a peripheral zone close beneath the nuclear 
membrane. With Twort’s combination of neutral red and 
Lichtgriin (PI. 17, figs. 17-20), or when preparations stained 
with iron-haeinatoxylin are counter-stained with Lichtgriin 
(figs. 14-16, 21), the peripheral zone is coloured green, a 
reaction which indicates that achromatic elements predominate 
in this region, and that a true achromatic membrane is 
present enveloping the nucleus. The dense karvosome 
frequently shows a central lighter region in which one or 
two darker grains, doubtless of the nature of centrioles, can 
be made out. 
The numerous food-particles (chiefly ingested bacteria) 
which are present in the cytoplasm, and which take up the 
ordinary nuclear stains very strongly, render the precise 
study of the chromatin-grains very difficult ; but in some 
well-stained examples there seems to be distinct evidence of 
passage of chromatin-granules into the cytoplasm, where they 
may form a more or less irregular chromidial mass surrounding 
the nucleus or scattered through the cytoplasm, which, con- 
sequently, is coloured a more or less deep red with the 
neutral red combination (PI. 17, figs. 17-20). It will be 
necessary to return to this point in connection with the 
phenomena of budding. 
As has been stated above, the large amoebse in the liver- 
abscess may reproduce in the cultures in one of two ways : 
(1) by simple division with karyokinesis ; (2) by the forma- 
tion of endogenous buds. 
(1) Division. — The main features of the behaviour of the 
nucleus in this case make it clear that the process of division 
is a mitosis, and this is fully confirmed bv Major Liston's 
live observations. Unfortunately I have not been .able to 
obtain evidence as to the method in which the nuclear spindle 
is formed. In the earliest examples of division that I have 
been able to recognise the nuclear spindle is already fully 
formed (PI. 16, fig. 7), and the chromatin of the nucleus 
lies in the equatorial plate in the form of a number of rather 
irregular masses. In the later stages of division (PL 16, 
VOL. 57, PART 2. NEW SERIES. 11 
