380 K. MASUI: 
Spermatogonien, so scheint es kaum möglich, den Gedanken abzuweisen, daß 
die ringförmige Sphäre einen mechanischen Einfluß auf die Kerntheilung 
ausübt.” 
The amitotie division usually begins in the fission of the nucleolus (Figs. 
9, 12), being followed by that of the nucleus, while in some cases the 
nucleolus does not seem to divide (Figs. 8, 10). The nucleus seldom divides 
into three or more at the beginning of this division (Fig. 7). 
During the amitotic division the nucleus usually remains in the resting 
state (Figs. 8—14), and there is no formation of spiremes or chromosomes. 
But some of the spermatogonial cells in which the spiremes have been formed, 
are seen suddenly to increase in size and begin to divide amitotically (Fig. 
18). In such a case the spiremes gradually disappear, and the nucleus again 
enters into the resting state (Fig. 16). 
As the amitotic nuclear division is not followed by the division of the 
cell body, multinuclear cells are formed by it (Fig. 17). The nucleus thus 
formed by amitosis usually appears irregular in form and contains a small 
amount of chromatin granules which are scattered throughout the nucleus. 
Their nuclear organization is quite similar to that of the Sertoli-cells. 
II. The Spermatogonia. 
Spermatogonia in the earliest generation :—Only a few spermatogonial cells 
of the earliest generation are found in the testes of quite young amimals. 
As stated above, some of the spermatogonial cells are divided by amitosis, 
while the others are multiplied by mitosis, thus two kinds of cells are produced 
by the two methods of cell division. In the cells produced by mitosis, the nuclei 
are of large size, and numerous chromatin granules are scattered throughout the 
nucleus. These cells are the spermatogonia in the earliest generation. 
The number of chromatin granules gradually increases, which afterward 
arrange themselves along fine threads in an entangled mass around the nucleolus 
(Figs. 22, 23). Then the chromatin spiremes are formed which are distributed 
throughout the whole spaze of the nucleus, meanwhile the nucleolus begins 
to disappear (Fig. 22) or to break into small pieces (Fig. 20), leaving a 
plastin remnant. The spiremes now become gradually denser and thicker, 
