MATURATION OF OVUM OF ALCYONIUM DIGITATUM. 95038 
Furthermore I believe, though I cannot state so positively, 
that: 
(g) A process takes place that may roughly be compared 
to the formation of polar bodies, but they disintegrate and do 
not leave the cell. So far as I have ascertained nothing in 
the shape of extrusion takes place. It is, however, curious 
to note that the nearest account that I have been able to find 
of like behaviour in an egg nucleus is that of Stoeckel.' 
This author found in a human ovary certain of the ova con- 
taining large nuclei, the membrane of which, as a rule, was 
well marked, but “‘ oft geht diese scharfe Abgrenzung auch 
verloren. Die Konturen werden unregelmasseg Zackig, ver- 
schwommen.” . . . Stoeckel believed that these changes in 
form were the beginning of amitotic nuclear divisions, giving 
rise to binucleated ova, of which he found several. I know 
of no other assumption of the direct division of an egg 
nucleus before fertilisation. 
(h) The first segmentation nucleus is derived from the 
male pronucleus, though it is quite possible that chromatin 
equal in amount to that of the male may also be derived from 
the female pronucleus, though all trace of the latter has 
been lost. 
If the foregoing statements be only partially true, it is 
obvious that a great gulf is fixed between the maturation 
processes in the egg of Alcyonium and all hitherto described 
cases. For this reason I am very loth to do more than state 
the bare conclusions to which I have come. To the best of 
my belief, no author has described amitotic nuclear divisions 
in the formation of polar bodies. We seem to have to deal 
with perfectly abnormal conditions. Nevertheless we are 
forced to admit that the maintenance of the individual 
parental chromosomes in a fertilised egg-cell is not universal. 
On the contrary, all trace of the chromatin of the original 
egg nucleus is lost. Furthermore, there are several instances 
among the protozoa of the breaking up and reorganisation 
1 W. Stoeckel, “Uber Theilungs-vorginge in Primordialeiern bei einer 
erwachsenen,” ‘ Arch, f. mikr. Anat.,’ Bd. liii, 1898. 
