Mottier . — Development of the Spermatozoid in Char a. 251 
results. Although we found such a body present during certain stages of 
mitosis, yet we could not trace it from one cell-generation to the next, 
and our conclusion was that it was only a temporary organ. There is no 
question but that Ikeno has observed a similar phenomenon in the sper- 
mogenous cells, for in all known cases wherever centrosomes are present in 
vegetative cells, they are to be observed also in reproductive cells of the 
same organism. The behaviour of these structures in the spermogenous 
tissue, as described by Ikeno, seems to be similar to that which I have 
mentioned for the vegetative cells; for Ikeno (’ 03 , pp. 70, 71) states 
explicitly that, in the ‘ aster ’ and c diaster * stages of mitosis, the cen- 
trosomes are only occasionally to be observed, and that they disappear at 
the end of each mitosis and reappear again at the beginning of the next 
successive karyokinesis. 
In the last division of the spermogenous tissue the cubical cells divide 
obliquely, and the two resulting cells, which are triangular in shape, are not 
separated by a cell-wall. This division differs from the preceding division 
in that the centrosomes are always present (loc. cit., pp. 74, 75), so that each 
triangular protoplast, which is to become transformed into a spermatozoid, 
has a centrosome that eventually passes into an angle of the cell (loc. cit., 
Figs. 22-26). This centrosome now elongates somewhat and places itself in 
close contact with the inner contour of the cell, so that it appears to have 
arisen as a local thickening of the plasma-membrane (Hautschicht). Out 
of this elongated centrosome the two cilia now grow. As soon as the 
cilia have begun their development, a thread or band-like cytoplasmic 
differentiation appears, which grows in the direction of the anterior end of 
the future sperm, and finally connects the nucleus with the centrosome 
(loc. cit., Fig. 31). According to this statement, therefore, the centrosome-like 
body gives rise to the cilia only, whereas the specially differentiated cyto- 
plasmic thread, or band, is of another origin. £ Bald nachdem die Cilien 
sich zu entwickeln begonnen haben, rundet sich die Spermatide ab (loc. cit., 
Figs. 29, 30), . . . der cytoplasmatische Fortsatz beginnt sich auszubilden 
und wachst nach der Richtung des vorderen Endes des jetzt sich bildenden 
Spermatozoids hin, um schliesslich das Zentrosom zu erreichen, so dass 
dieser Fortsatz den letzteren mit dem Zellkern verbindet (loc. cit., Fig. 31).’ 
This statement does not harmonize with Ikeno’s figures. It would 
seem from his Figs. 30 and 31 that the ‘Fortsatz 5 mentioned, connecting 
nucleus with the elongated, cilia-bearing band is derived from the cilia- 
bearer itself, as represented in his (loc. cit.) Figs. 29 and 30, and not as 
a separate formation. 
If Ikeno’s statement be correct, then the development of the specialized 
cytoplasmic band, which is known as the blepharoplast, differs in Mar- 
chantia from that known in all other Archegoniates, for, in the Ferns 
and zooidogamous Gymnosperms, the centrosome-like body gives rise 
