CARNOY S CELL RESEARCHES, 491 
left neighbours ; or they may arrange themselves in the star 
with one limb directed outwards, and the other hanging in- 
wards directed towards the axis of the figure ; then the bends 
of the U’s curve in towards the pole, and both limbs bend in 
towards the axis (fig. 13), and unite with the limbs of two 
vis-a-vis; the internal limb of any U joining with the external 
limb of one vis-a-vis and with the internal limb of another 
(fig. 14). It will be seen that in this case the daughter-nuclei 
present a disposition that reveals the organic axis of the 
nucleus; seen from the poles, the chromatic filament has a 
radiate arrangement, and seen from the side it appears as loops 
running parallel to the axis. In some cells (Arachnida, some 
Crustacea) the daughter-nuclei preserve this structure perma- 
_nently, and it is then seen that at the next division they divide 
along the same axis as at first, and in a plane parallel to that 
of the first division. (It will be remembered that Rabl has 
recently (Morphol. Jahrb.,’ 1884, 2 Hft.) shown that two 
poles can be made out in cells of Salamandra during the 
first prophase.) In some cases the union of the segments is 
devoid of any apparent regularity ; the daughter-stars appear 
to break up and the segments to unite without order. 
The reconstitution of the filament generally follows closely 
on the arrival of the stars at the poles. But it may be delayed 
until after the formation of the nuclear membrane. It is pos- 
sible that in some cases, when successive divisions succeed one 
another very rapidly, the reconstitution of the filament may 
never be completed. 
As to the Spindle.—The spindle is formed out of the karyo- 
plasm. This highly important proposition has been asserted 
before. It is now definitively proved by the discovery of 
numerous examples of nuclei containing a fully-formed spindle 
within a perfectly intact nuclear membrane (figs. 15, 
17, and 18). Carnoy has now observed some thirty of such 
cases, in which the persistence and perfect integrity of the 
membrane were so evident as to leave no room for the least 
doubt. 
The fibrils of the spindle are formed by the rearrangement 
