3 ÏO 
Vi L. SOÓS 
It was described in Helix first by Platner, and since then many authors 
have found them in different forms. Platner named it with a term 
given by Bütschli nebenkern which term has since then been very often 
used. This organ can appear in very different forms even in the same 
sort of cells according to the different stage of its development, therefore 
it has been named variously by different authors. Heidenhain called 
them pseudochromosomes, Meves chondriomites, or mitochondria. Gold¬ 
schmidt (32) is of the opinion that this organ is identical with the 
chromatic apparatus described by R. Hertwig from the Protozoa, and 
Popoff (94) accepted Goldschmidt’s suggestion. It seems that the inter¬ 
zonal body of the American author» belongs partly to it. The Figs. 1., 
3. and 4., Pl. VIII., which were drawn from preparations fixed with 
Bouin’s picric-formol either do not show this cell-organ, or do so very 
insufficiently, because this mixture, as mentioned above, is not well 
adapted to preserve it. It is, however, very clearly visible on Fig. 2., 
Pl. VIII., drawn from a Flemming preparation. This figure, though it 
shows a later stage in development, yet, in spite of this, exhibits the 
connection of the cromosomes and nebenkern. This connection is so 
regular that we must suppose a closer relation between the chromoso¬ 
mes and nebenkern. Popoff (95) interpreted this connection as follows : 
The nuclear sap is during synapsis continually increasing, in consequence 
of which the nuclear membrane swells. At length the membrane cannot 
balance the pressure and at its weakest part breaks through. Through 
this opening fluids diffuse from the nucleus to the cytoplasm which also 
seizes minute chromatin corpuscles, and these latter build up the chro¬ 
matic apparatus. The stream also seizes the open ends of the chromo¬ 
somes, therefore they become loop shaped, and their ends become 
naturally attached to the nuclear membrane. 
The chromatin condenses in spherical chromomeres arranged regu¬ 
larly in the linin of the loops, they are thus rosary shaped. The chro¬ 
momeres are connected rather loosely, therefore the chromosomes often 
disintegrate into their constituent parts. 
The chromosomes in the next stage split (Pl. VIII., Fig. 1.). The 
half threads like the whole ones consist of spherical chromomeres. They 
are always arranged symmetrically side by side in pairs in the achro¬ 
matic ground substance. I have never found split chromosomes having 
alternated chromomeres ; Popoff (94) made the same observation in 
Paludina. 
The chromosomes synchronously with their splitting scatter through 
the nucleus, while the daughter chromosomes separate from each other, 
as is seen on Figs. 1. and 3., Pl. VIII., the former showing an earlier, 
