KARYOKINESIS AND ITS RELATION TO FERTILIZATION. 179 
kinesis during recent times; by means of them Flemming’s 
discovery first attained its full value, as van Beneden clearly 
appreciated (1. c., pp. 328, 379, and 380). 
Flemming had already (58) given many minute details of 
the process, and Rabl (165) has recently added a very careful 
description of metakinesis in the connective-tissue cells of the 
Salamander. The figures 9 and 10 copied from Rabl (in which, 
as in fig. 11, the nuclear membrane is no longer evident) give 
a rough representation of the course of events. 
Metakinesis now leads to the next—the fourth—stage, that 
of the “ daughter-stars ”’ (Dyaster), fig. 11. This commences 
when the open limbs of the loops of the chromatic threads, 
passing along the spindle figure towards the poles, no longer 
touch at the equatorial plane. The angles of the loops of each 
polar half approach one another, the open limbs lose the di- 
rection parallel to the spindle figure which they had during the 
separation, and resume that corresponding to the equatorial 
plane, so that in a polar view one sees at each pole the figure of 
a star, the daughter-stars. The angles of the loops do not 
here touch one another, so that each shows a light spot which 
is the “hilus ” of Retzius (172). Flemming believes the loops 
of the daughter-stars to be all of equal length and symmetrical, 
in which he is opposed by Rabl (cf. the figures copied from 
the latter). 
As alast phase there appears immediately after the daughter- 
star the daughter-skein or “ dispirem” of Flemming. The 
threads become still shorter and thicker, and according to 
Rabl’s description the polar surface of the daughter-nucleus 
lies at the polar area where the above-mentioned “hilus ”’ 
is situated; the limbs of the loops bend round towards the 
former equator, and meet at that surface of the nucleus directed 
towards the antipole. In plant-cells Heuser and Strasburger 
come to similar conclusions, although, according to Guignard 
(84) and Strasburger (191), the hilus may be absent. This 
stage is followed, when division of the cell ensues, as it does in 
most cases, by division of the cell-protoplasm, which 
is brought about, essentially, by a continually deepening con- 
