Opalina. 
Oo 
57 
Fig. 25. A section of another nucleus similarly preserved and stained. The 
chief lines of achromatic granules at the upper surface of the section are accurately 
shown; the other granules are drawn free hand. > 2000 diameters. 
Figs. 26 and 27. Sections of other nuclei in which the fibrillar structures 
were more clearly seen. In Fig. 27 the achromatic granules and films lying 
beneath the chromatin net in the center of the nucleus are not drawn. Coros. 
subl.-acetic acid, safranin and light green. > 2C00 diameters. 
Figs. 283—31. Four sections showing the whole of one nucleus and, in 
Fig. 29, part of the cytoplasm. The chromatin spherules are numerous; the 
nucleolus is vacuolated. Except the very delicate chromatin net, whieh was 
difficult to see, all the chromatin structures present are drawn. In Fig. 29 the 
thickness of the pellicula (green) is uncertain, for the section was a little oblique. 
The interruption of the pellicula, as shown, was undoubted. LEctosarc films, granules, 
fibrils (?) and spherules, green; endosare spherules pink; endosare granules, films 
and fibrils (?), green. > 2090 diameters. . 
Fig. 31a. On optical section of a macrogamete or macrogamete parent cell 
of O. dimidiata from a tadpole of Bufo vulgaris, infected 19'/, hours. The ectosare 
spherules are yellow, the endosare sphernles red. The nuclei are not drawn. 
Acetic-carmine. >< 1010 diameters. 
Plate XVI. 
Living Opalina intestinalis. 
Except in Fig. 34, the anterior end of each nucleus in toward the top of 
the plate. 
Fig. 32. The anterior end of a daughter cell whose nucleus is in a telophase 
of mitusis. Only the nuclear structure is shown. This was the posterior nucleus 
of the parent cell, as is indicated by its pointed anterior end. Eight chromosomes 
are seen in the anterior end of the nucleus; in the posterior end but seven can 
be seen, the eighth lying in the lower half of the nucleus below the right hand 
chromosome of the upper group of four. All the structures in the nucleus were 
remarkably clear, as clear as in the best stained preparations. The achromatic 
granules of only the upper half of the nucleus are shown, except that in the 
anterior end of the nucleus two rows of granules at a lower level are also drawn. 
X 1010 diameters. 
Fig. 33. A nucleus drawn five to forty-five minutes after active swimming 
movements of the animal ceased, the cilia being then but slightly active. The 
grauules of only the upper third of the nucleus are drawn. A few endosare 
spherules and large granules of the cytoplasm are drawn for comparison. Eight 
chromosomes are seen in the anterior nucleus; three of those in the posterior 
nucleus are hidden. This nucleus was later almost completely isolated from the 
body, being held at one end by part of the broken body. It withstood uninjured 
the wost violent currents produced by intermittent pressure on the cover-ylass 
and after three days was entirely unchanged, except that the chromosomes seemed 
more nearly spherical and the achromatic granules were lies refractive, some 
having disappeared. >< 1485 diameters. 
Fig. 34. A pair of nuclei from an animal with active cilia, which was held 
immovable by pressure between a hair and the cover-glass. Eighteen hours after 
all movements of the cilia ceased the nuclei were in the same condition. Eight 
(or nine) distinct chromatin masses are in the anterior nucleus (one chromosome 
24* 
