CARNOY’S CELL RESEARCHES. 489 
their filament by one extremity only, and stand out perpendicu- 
larly to the direction of the filament. In this case the extremity 
by which they are attached is bifid, as in the pollen-cells of 
Fritillaria {see Strasburger, ‘ Die Controversen,’ &c., Taf. 
xiv, figs. 68, 69; or Flemming, ‘ Zellstz., Taf. viii, fig. 7). 
Slightly-curved segments are apparently attached to their fila- 
ment by the back or side; in the case of deeply-curved or 
U-shaped segments it can be clearly made out that the filament 
passes inside the bend of the U. 
Fission of the Segments—Metaphase (‘dislocation de la 
couronne”’).—The separation of the mother-star into two 
groups which travel to the poles is generally, as in hitherto 
studied animals and plants, preceded or accompanied by fission 
of the segments. In the majority of cases this fission is longi- 
tudinal. Straight segments may split at one end and open out 
gradually. Slightly-curved and U-shaped ligaments may split 
simultaneously throughout their whole length and along a 
strictly median line; or straight or slightly curved segments 
may split along a median line that becomes sinuous at the 
extremities of the segment, cutting through the ends, not in 
the middle, but at the angles (figs. 6 to 10), so as to produce 
two diagonally opposite hook-shaped moieties. This curious 
mode of separation, which appears to be by no means un- 
common, appears to me very interesting as forming a transi- 
tion between strictly longitudinal fission and transverse fission. 
In some cases the fission is transverse. In Astacus, Scolo- 
pendra, and Forficula, Carnoy has observed the fact in the 
most positive manner, and in other groups has frequently 
met with appearances which lead him to regard it as very 
probable. 
The moieties produced by any of these modes of fission are 
in some cases destined to travel to opposite poles of the spindle, 
in other cases not so. A kindred fact to this last is that the 
fission may be retarded, and take place at the poles in the 
Dyaster stage, as in the fig. 86 of Flemming’s ‘ Zellstz.,’ p. 258. 
It is by no means impossible that longitudinal division may 
in some cases be entirely absent. It is, at all events, now 
