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ANNIE MATTHEWS. 
7. Segmentation. 
The newly fertilised egg is of about 05 mm. diameter, 
opaque, and fall of reddish-yellow yolk. It has accordingly 
to be rolled round in a suitable vessel of sea-water in order 
that the lobes and segments may be seen. Hence observa- 
tions are less easy than in the case of the transparent eggs of 
Echinus. The eccentric oosperm nucleus is somewhat oval in 
shape, and resembles that figured by Hill (5). The problem 
of the maturation and fertilisation of the egg together with 
the first divisions of the oosperm nucleus was not attempted, 
as it is rather outside the scope of this work. 
The outstanding feature of the early segmentation in A. 
digit at um is its great irregularity of procedure. It would 
seem as though the many ways of reaching the morula stage 
were highly variable and unimportant, the resulting embryos, 
however, being apparently of one kind. This bears out 
Wilson’s remarks on Renilla (16), and is the first of a series 
-of similarities shown during the development of these two 
Alcyonaria. Ho polar bodies are extruded and no outward 
sign marks the time of actual fertilisation. Before any per- 
manent alteration in appearance occurs the ovum seems to 
make violent but unsuccessful attempts at division, i. e. the 
spherical egg becomes temporarily polygonal, the surface 
being drawn out into irregular high ridges with corresponding 
depressions, possibly witnesses of internal activity (Text- 
fig. 26) . These ridges disappear after some time and the egg 
returns to its spherical condition. The whole process may be 
repeated with no apparent result. In one case the ridges 
softened down into eight vaguely defined, lighter coloured 
areas which covered the whole surface of the egg, but these 
•eventually disappeared, leaving a spherical egg as before. In 
other cases the ovum became temporarily long and oval, but 
regained its globular shape later. In artificial fertilisations 
the time elapsing between the adding of sperm to the bowl of 
ova and the above-described attempts at division varied from 
half an hour to two and a half hours in different cases. The 
