457 
Sexual Nuclei in Liliilm Mar tag on. 
has very much increased. Perhaps they may be derived 
from the breaking down of the smaller nucleoli. The thread 
itself is much thickened, often irregularly: in many places 
the drops of nucleolar matter adhering to it have elongated 
in the direction of the thread. This suggests at once 
that the nucleolar matter is applied to the thread with the 
purpose of thickening it. Where the thread is of fairly 
uniform thickness for some distance, two rows of dots can 
sometimes be made out in it with very high powers. The 
picture is usually confused by the twisting on itself of the 
thickened and rather flat thread (Fig. 12 a). Where the 
double row can be made out with any precision, which at 
this stage is only in preparations from Flemming material 
stained by the orange method, the ribbon itself is seen to 
be of a reddish tinge and the dark dots to border it on either 
side. The nucleolus usually becomes vacuolated before losing 
its clear outline. 
Before finally passing into the contracted state the dotted 
ribbon just described begins to close round the nucleolus. 
This has become washy and vacuolated. Large fragments 
are broken from it : some of these, or the main nucleolus 
itself, are often sickle-shaped. Smaller fragments are attached 
to the chromatic ribbon. The outline of the nuclear mem- 
brane can hardly be traced. 
The nucleus now enters the period of synapsis, in which 
it remains for some time, probably several days. The 
whole chromatic thread contracts into a ball, leaving a large 
part of the nuclear cavity empty. This cavity is some- 
what swollen : the membrane can be followed in places, 
but is often broken and always obscure (Fig. 13). The 
chromatic ball is always close to one side of the nuclear 
cavity, and partly surrounds the half-dissolved nucleolus, 
which is often sickle-shaped (Fig. 13). A general view of 
the whole structure is best gained from a thick alcohol section 
stained with methyl-green and fuchsin, as the nucleolar matter 
is then sharply distinguished from the chromatin. Microtome 
sections are unsatisfactory, as the chromatic thread as well 
H h 2 
