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SYDNEY .T. HICKSON AND J. 'P. WADSWORTH. 
our interpretation of this line is correct or not, the fact 
remains that there is a very marked difference between the 
ineganncleus of Dendrosoma and that of other Acinetaria 
except Lernajophrya we have examined in this respect. 
In referring to the meganucleus of Acineta papillifera, 
Martin (24) writes : “ Generally in whole stained preparations 
numerous spherical dark areas are to be seen resembling the 
so-called “ Binnen-korper ” of the Infusoria. In section, 
these structures, as in the case of some Infusoria and Dendro- 
cometes, are found to consist merely of local thickenings in 
the mesh of the nuclear network, and therefore resemble 
karyosomes rather than true nucleoli.” 
In Lermeophrya, so far as our observations go, the 
meeranucleus resembles that of Dendrosoma. 
In Acineta tripharetrata, according to Entz (13), the 
substance of the meganucleus appears to resemble that of 
Dendrosoma and contains a number of sharply defined bodies, 
but there is a distinct nuclear membraue. 
Collin (7) describes the meganucleus of Bphelota gemmi- 
para as consisting of “grains chrom'atiques de forme variee 
sur un substance achromatique,” but he finds also a distinct 
isolable nuclear membrane. 
In the iron-brazilin preparations a faint yellow colour can 
be seen in the thicker sections between the granules, and iu 
iron-luematoxylin and congo-red preparations a faint pink 
colour may be seen in the same place, indicating perhaps that 
the matrix in which the chromatin granules float is to some 
extent capable of taking a faint oxychromatic stain, but no 
structure is seen in it even with the highest powers (Zeiss 
2 mm.) of the microscope we have used in the best light. 
There can be little doubt that the granules are mainly 
composed of chromatin. They give the characteristic stains 
with iron-lnematoxylin, iron-brazilin, safranin, and thionin. 
They are usually spherical in shape, but occasionally irregular- 
shaped granules and large lumps (fig. 51) are found in the 
course of the band. 
'I'he variability in size may be seen by a comparison of figs. 
