400 
Philippine Journal of Science 
1919 
In stained preparations the meganucleus is the most con- 
spicuous intracellular object. It takes the stain deeply and it 
is only by good differentiation that its true structure is seen. 
The shape of this nucleus is quite characteristic. In the vege- 
tative state of the cell its normal form might be said to be 
sausage-shaped to reniform, but it shows an orderly and pro- 
gressive series of form changes that develop until it has finally 
completely curved upon itself to form a circle with the two ends 
of the nucleus in apposition. The micronucleus is usually lodged 
in the concavity of the meganucleus and tends to become en- 
closed by it. The possible significance of these form changes 
will be discussed later. 
Fig. 2. Cytoplasmic structure and meganuclear and micronuclear relations in Balantidium 
haughwouti. 
in stained preparations the meganucleus measures on the 
average 19.83 n in length by 7.5 ^ in width. In general shape 
it closely resembles the meganucleus of Balantidium coli, and 
that of B. entozoon as figured and described by Stein, who ap- 
pears to have noticed the same variation in form. 
In deeply stained specimens the meganucleus appears to be 
formed of a solid mass of chromatin. Careful differentiation 
shows the chromatin to be distributed in the form of fine gran- 
ules more or less closely packed together. The appearance 
varies, however, so that the finer structure frequently appears 
as a reticulum of varying texture. Many nuclei show areas that 
appear more or less alveolar — that is to say, give the appearance 
of a network of chromatinic material surrounding clear spaces 
