366 K. MASUI: 
VI. The Transformation of Spermatids. 
The spermatids, after passing through a brief resting stage, begin to 
develop into spermatozoa and the chromatic materials soon collect on the 
surface of the nucleus (Figs. 63, 64). 
The important changes which occur during the transformation of the 
spermatids are those connected with the centrosome. With the formation of 
the mass of the mitochondria, the centrosome, which up to this time remained 
as a single body, begins to divide (Figs. 63, 65). Of these two centrosomes 
thus formed, the one which is somewhat rod-shaped, comes to be placed in 
contact with the nuclear wall, while the other, which has a spherical shape, 
remains for a time near the periphery of the cell, the two being connected 
by a fine filament (Fig. 63). Soon after this the peripheral centrosome 
again divides (Fig. 65), and three bodies are thus formed, the original central 
one lying close to the nuclear wall, and the inner and outer are formed 
of the parts of the peripheral centrosome. Of these latter two, the inner one 
travels toward the central centrosome, and comes to be placed in closs contact 
with it, while the outer remains at the place of its formation and changes 
its shape to a disk or a sphere (Fig. 67). Meanwhile a fine filament is seen 
to proceed from the inner of the peripheral centrosomes backward towards the 
surface of the cell, which later becomes the axial filament of the spermatozoon 
(Fig. 68). Together with the division of the centrosome the archoplasm 
appears first near the mitochondrial mass, but soon moves alongside the 
nuclear wall, to occupy its final position directly opposite to the mitochondrial 
mass (Figs. 66, 67). | 
In the horse I could not follow directly the origin of the archosome 
either from the idiozome or independently in the cytoplasm. WopsEDALEK 
(135) states that in the pig the archosome is formed from the sphere, just 
as Meves (1899) showed long ago in the guinea-pig, the sphere of the 
spermatid according to MEYES is homologous with the idiozome of the 
spermatogonium or spermatocyte. 
At any rate the sphere thus formed finally passes to occupy its 
position at the apex of the unripe spermatozoon and there becomes the 
