164 Davis. — Nuclear Studies on Pellia . 
Mottier (’00) for Dictyota. Nevertheless, the writer holds the 
view that these structures in Pellia have a relation, although 
perhaps very distant, through phylogeny to typical asters, and 
they will be called such in this paper. 
The first indication of an aster in the spore of Pellia is 
a differentiated area of kinoplasm near the nucleus, dis- 
tinguished from the surrounding cytoplasm by its dense 
granular character, which stains deeply, its freedom from 
plastids, and the absence of alveolar structure. The writer 
believes that the asters arise independently of one another 
in two distinct regions of kinoplasm. They would not then 
be related as asters, although it is quite possible that their 
substance, the kinoplasm, may have come from the same 
source. 
In justice, however, we should first note some facts that 
to many will seem strong evidence of behaviour quite the 
opposite to what has been suggested, and fully in accord 
with the activities expected of typical asters. It is not unusual 
to find the kinoplasm around a nucleus massed at one side 
in a very conspicuous manner. Such an example is shown 
in Fig. 22, a nucleus in synapsis just previous to division. 
However, the writer was never able to differentiate an aster 
in such a mass of kinoplasm, and in his studies has never 
found a nucleus with a clearly-defined solitary aster beside 
it. This is a very important point, and the search was per- 
sistent. The region of kinoplasm at the side of the nucleus 
may be large, but at this time it is homogeneously finely 
granular. The asters appear on opposite sides of the nucleus, 
sometimes applied to the nuclear membrane, sometimes at 
a distance from it. 
Only one example was observed where the asters were 
separated by much less than 1 8o°, and this specimen is shown 
in Fig. 23. In this case the distance between the asters is 
hardly more than 90°. To many the discovery of one such 
instance will entirely invalidate negative evidence, and they 
will hold that here is presented a stage in the separation 
of two daughtqr-asters that were derived from one. One 
