766 THOS. H. MONTGOMERY, JR. 
(3) Mixed nucleoli, those composed of a mixture of plasmosome 
and chromatoid substance; Maziarski and others consider these 
an intermediate stage between the other kinds of nucleoli. 
We will adopt Blackman’s term of ‘karyosphere’ to denote 
compounds of nucleoli, of whatever kind, with chromatin retic- 
ulum or chromosomes. Karyospheres are therefore containers 
of some or all of the chromosome substances, and correspond in 
part with Carnoy’s ‘nucléoles-noyaux.’ In the germ cells they 
are limited mainly. to primary oocytes and spermatocytes. The 
following kinds of them are known: 7 
(1) Combinations of plasmosomes and allosomes, in which the 
latter are more generally apposed to, more rarely imbedded in, - 
the plasmosome. These are frequent in insect spermatocytes, 
especially in Hemiptera. They are separate from the nuclear 
reticulum, and from autosomes. 
(2) Associations of plasmosomes with both autosomes and 
allosomes, best known in the spermatocytes of myriapods after 
the researches of Blackman (’03, ’05, ’07) and Medes (’05). 
These may at certain stages contain all the staining substance of 
the nucleus. In some myriapods the plasmosome constituent 
would seem to be lacking. They are the most complex of all 
nuclear structures. 
(3) Associations of autosomes or ordinary chromosomes with 
a plasmosome, which differ from the preceding kind in lacking 
allosomes. These are known in germinal vesicles of certain echin- 
oderms, mammals, araneads, and Paragordius, and spermatocytes 
of certain insects. Their genesis is as follows: A nucleolus de- 
velops, more or less of the nuclear reticulum moves into it, and in 
the prophases of mitosis chromosomes emerge from the nucleolus. 
As incipient karyospheres of the third kind might be considered 
cases where chromosomes terminate against nucleoli without 
being wholly enclosed in them. Such are the chromoplasts of 
Batrachoseps, according to Eisen (’00) and Janssens (’05); and 
such also would be the nucleolar relations we have described in 
Kuschistus.” 
#2 Nichols (710) has tried to relate the different kinds of nucleolar complexes, 
and refers them all to the common physiological basis of a transfer of chromatin 
material to, and a later withdrawal of it from, the plasmosome. 
