SPERMATOGENESIS OF EUSCHISTUS , 787 
of spheres. But it must be said that none of these writers except 
Vejdovsky have paid particular attention to their origin. Pantel 
and de Sinéty leave the question open, though they show that 
the ‘pseudochromosomes’ arise in close contact with the nucleus. 
Another group of investigators (Dumez, Janssens, Popoff, Was- 
silieff, Goldschmidt, Buchner, Jorgensen) hold them to be of 
nuclear origin, for the following reasons: In the pachytene stage 
of the spermatocytes the chromosomes are frequently, though 
not in all objects, definitely oriented, radiating in a “bouquet 
stage’ towards the distal pole of the nucleus, and the idiozome 
lies at that pole in the cell body; near that pole of the nucleus 
the mitochondria make their first appearance. This position 
of the mitochondria, close to a particular pole of the nucleus, 
is taken to mean that they are produced there by some nuclear 
activity. Most of these writers maintain that they are engen- 
dered by actual emigration of chromatin particles out of the 
nucleus at that pole, as indicated especially by Janssens, Was- 
silieff, Jérgensen and Buchner. This idea of chromatin emi- 
gration has been particularly instigated by Goldschmidt’s view 
that the mitochondria belong in the class of chromidial forma- 
tions. In Euschistus we found in the resting spermatogonia 
a particular chromatin plate upon the nuclear membrane, 
and this is invariably at the point where the idiozome lies; but 
in these cells there are no demonstrated mitochondria present 
around the idiozome. In the spermatocytes of this species 
there is another chromatin plate, here produced by the ends of 
two or, three chromosomes, again always at the pole where the 
idiozome lies; in the close vicinity of this idiozome the first 
mitochondrial chains make their appearance. Pantel and de 
Sinéty found in Notonecta that the mitochondria arise between 
the idiozome and the nucleus, therefore in relation to both. In 
EKuschistus it is hard to make sure whether the mitochondria 
arise from the cytoplasm, from the idiozome or from the nucleus. 
But the fact is that they originate in the distal pole of the cell, 
close to the idiozome and the nucleus, therefore it is probable 
they are produced by either idiozome or nucleus or by a joint 
action of these. We saw previously that the idiozome probably 
