xv, 4 De Leon: Balantidium Haughwouti 401 
or areas of achromatinic substance. The whole is inclosed in 
a delicate nuclear membrane. 
Fig. 3. a, b, and e, Meganuclei of the reticulate type (a, superficial; b, middle; and c, deep 
focus) ; d, e, and f, optical sections of a reticulate meganucleus; g, meganucleus viewed 
from its convexity; note the extreme thinness of the “crown” of the nucleus under which 
lies the micronucleous ; h, bipartite meganucleus ; micronucleus partly shown ; i and j, 
meganuclei of granular type ; k, meganucleus of alveolar type. 
The finer structure of the meganucleus, as seen in the normal 
vigorous infusorian, is that of an evenly distributed network of 
chromatin granules compactly arranged. This structure is, of 
course, only demonstrable in well-stained and properly extracted 
preparations. Irregular clumping of the chromatin into a series 
of groups which gives the appearance of a vacuolated nucleus 
has been interpreted by various investigators as supervening on 
unfavorable conditions and as presaging disaster to the organism. 
I see no support for such a supposition in this instance. All 
the individuals showing a nucleus of this type were vigorous- 
appearing cells, exhibiting no signs of the vacuoiation and dis- 
tortion so characteristic of the infusorian cell in distress. 
In addition to the regular series of incurving forms, other 
striking and interesting changes are seen in the structure of 
the meganucleus. Individuals have been seen in which there 
were two well-formed meganuclei in the cell. I am inclined to 
interpret this as, possibly, a result of abnormal distribution of 
the meganuclear anlagen in the ex-con iugant stage following 
syngamy, which process, however, I have not observed. 
