Hata, Mitosis in Nerve Cells. 289 
places (Fig. 23). When the acidophile particles centralize them- 
selves at one place, a circular space is produced. This space, 
however, appears to be filled by a fluid which also stains a red 
color after HERMANN’s method. Ina further advanced stage, 
these groups of the acidophile particles, with enclosed liquid, are 
covered by another chemical substance which stains a blue 
color by HERMANN’s method. This latter substance seems to 
be derived from chromatic substance, because, in this stage, 
the latter material accumulates around the former. The present 
writer observed also, in most cases, extremely delicate filaments 
which directly arise from each acidophile particle and further, 
these filaments fuse together. The significance of these fila- 
ments just mentioned will be discussed later on. 
IV. Comparison with results of other investigators. 
From the preceding descriptions of the mitotic figures, it 
is clear that during the mitotis of the nerve cell the arrange- 
ment of the chromosomes as well as the behavior of the nucle- 
olus is slightly different from that described in other kinds of 
cells by previous investigators. 
FLEMMING’ first described a peculiar modification of the 
mitotic figures which is clearly visible in the spermatocytes of 
the salamander. According to this author, the chromosomes 
in an early stage of the mitosis do not split entirely, but remain 
undivided at both ends, thus forming-an oblong figure. Each 
oblong divides again transversely into equal parts and forms 
U-shaped chromosomes which lie in corresponding positions on 
each side of the equatorial plane. This U-shaped chromosome 
is not single, but is formed by two daughter chromosomes 
which are connected at their tips. To this kind of mitotic 
‘ figure, FLEMMING has given the name ‘‘Heterotypical division 
or mitosis.”’ 
1 FLEMMING: Neue Beitrage zur Kenntniss der Zelle: Arch. f. Mtkroscop. 
Anatomie, Vol. XXI1X, 1887. 
In most cases, the U-shaped chromosomes divide again Jengthwise, and 
the four chromosomes of the same shape- are produced from a single oblong. 
This phenomenon is known as ‘‘tetrad’’ formation of the chromosomes. 
