398 K. MASUI: 
situated at the posterior part of the cell becomes now divided into two, and these 
lie side-by-side, being connected by a thick filament. The two centrosomes 
thus formed move apart from each other and come to be placed in such a 
way that the one lies close to the nuclear membrane, the other at some 
distance from it, and thus anterior and posterior centrosomes are produced. 
The latter send out a fie filament backwards towards the surface of the cell 
which later becomes the axial filament. 
10. The chromosome nucleolus or the accessory chromosome can be 
traced throughout the growth stage and the reduction division. The behavior 
of this chromosome is quite similar to that of the horse, but it can not be 
distinguished in the resting stage of the secondary spermatocyte and in the 
spermatid. 
11. The idiosome appears as a cytoplasmic body in the growth stage, 
and during the formation of the spermatozoa it becomes more and more 
conspicuous, till it assumes a small spheric body and comes to be situated 
in a depression at the anterior part of the nucleus. It seems to have no 
connection with the centrosome. 
12. The mitochondrial granules make their appearance abundantly during 
the growth stage. Their behavior is quite similar to those of the horse. 
13. Second pairing of chromosomes is not found, but as in the case of 
the horse incomplete fusion of the chromosomes is seen to occur, in such a 
case occasionally nine or ten chremosomes are counted. 
14. The chromatoid corpuscle can not be found, but during the reduction 
division a small spheric body stained faintly with iron-haematoxylin rarely 
appears in the cytoplasm, which however could not be observed in all the 
other stages. 
