xv, 4 De Leon: Balantidium Haughwouti 403 
ical and that the elongation and the consequent increase in size 
are early evidence of beginning nuclear division. 
This nucleus is invested with a delicate nuclear membrane 
very difficult to demonstrate. There appears to be a cortical 
layer of homogenous transparent material that stains very 
lightly with the nuclear stains. In the gross, it appears to be 
practically a structureless body. Carefully differentiated spec- 
e 
Fig. 5. a, A small meganucleus is present ; the micronucleus seems to have fragmented ; b, 
the meganucleus and its membrane have disappeared ; the cytoplasm contains chromatinic 
bodies of unknown nature ; c, the meganucleus has disappeared leaving a body that appears 
to be its membrane ; the micronucleus appears in a distinct capsule ; d and e, early and 
late stages showing the incurvation of the meganucleus about the micronucleus. 
imens show, however, that within this achromatinic cortical 
layer there lies a minute chromatinic granule, or a collection of 
granules irregularly distributed on a reticulum. This heavy 
achromatinic cortex is not present in the micronucleus of either 
Balantidium coli or B. falcifarum. 
It is a little difficult to determine how much of this “cortex” 
is plastinoid substance or how much of it represents nuclear 
