322 Wager— On the Sir tic lure at id 
strands which still connect it to the wall of the oogonium (Fig. 
9). The nuclei at the same time undergo changes leading up 
to division. The nucleoli disappear and the network appears to 
divide up into chromosomes and contracts towards the middle 
of the nucleus in a very characteristic manner (Figs. 8 and 9). 
The network of chromosomes takes on a reddish tinge instead 
of a blue one and the nuclear membrane is very distinct. There 
can be no doubt, as will be seen later, that this contraction of 
the nuclear network, which gives the nuclei a very character- 
istic appearance at this stage, is preliminary to the division 
of the nuclei which takes place shortly afterwards. The 
majority of the nuclei are now to be found in the periplasm, 
and they gradually become more and more restricted to this 
layer. Meanwhile, however, nuclear division actually begins. 
Each nucleus divides into two, karyokinetically, and the 
appearance presented by an oogonium at this stage is shown 
in Fig. 9, in which a number of nuclei are to be observed 
in the periplasm which have undergone division, as well as 
nuclei in the centre still undergoing division. The various 
stages of division, so far as I have been able to observe them, 
are given in Fig. 28 (1 to 5), and are typically karyokinetic. 
While the division of the nuclei is taking place, a dense, 
very deeply stained blue, mass of protoplasm appears in the 
centre of the not yet completely differentiated oosphere. 
This appears at first sight to be completely homogeneous, 
but on closer examination is found to be made of a dense 
mass of granules closely packed together and more or less 
sharply marked off from the rest of the protoplasm. This is 
probably what was described by Dangeard (’ 90 ) as an oil- 
globule, and was mistaken by Chmielewsky (’ 89 ) for a nucleus. 
Dangeard’s observation that this substance disappears on 
soaking the tissue for a long time in chloroform, was probably 
due to the fact that it is not so apparent in some oogonia as 
in others, although it is generally present, even when casual 
observation of a thick section might lead one to the con- 
clusion that it was absent. That it is not oil is proved by 
its structure and by the fact that oil is not present except 
