Mr M c Dowall, A further note on the eggs, etc. 
613 
A further note on the eggs of the hermaphrodite Angiostomum 
nigrovenosum. By S. A. M c I)owall, M.A., Trinity College. 
[. Read 26 October 1908.] 
A re-examination of the material has rendered necessary one 
or two corrections in my preliminary note on the nuclear pheno- 
mena in these eggs. ( Ganib . Phil. Soc. Proceedings, Vol. xm, 
Pt. v, pp. 309—312.) 
A ring formation does take place after the contraction-phase, 
but the rings appear not to be completed, for the ends of the 
chromosomes do not fuse. 
The rings open out, often forming cy-shaped chromosomes 
which may or may not become V-shaped before they finally flatten 
into the pseudo-spireme. As a rule the w simply becomes more 
and more flattened until a straight strap is formed. 
In the next stage two nodal bodies seem to appear earlier 
than the rest, and they are, for a time at least, decidedly larger. 
Probably these are the forerunners of the large double-chromo- 
some mentioned in my previous note. 
Sometimes there are only five double chromosomes ; whether 
this is due to the section or no, I am still uncertain. 
It is just possible that the nucleolus has some important function: 
in the secondary-reticulum stage it seems occasionally to suffer 
unequal division, the larger part disintegrating immediately, the 
smaller persisting for a time ; but this is uncertain. 
