746 
Digby .— The Somatic , Premeiotic, and 
III. Second Meiotic Division. 
Prophase. 
The first indications that the nuclei have entered upon the reconstruc¬ 
tive prophase stages are the disappearance of the spindle fibres and the 
reconcentration of the linin portions (Fig. 74). The nucleolus, which when 
first formed in the telophase of the heterotype was of a chromatic staining 
nature, has by now become cytoplasmic in staining reaction. No nucleolar 
budding or ‘ body ’ formation has been observed in the homotype divisions. 
The nucleolus remains spherical and colourless, and is apparently ejected 
into the cytoplasm as the chromosomes collect on the spindle. 
Once more the halves of the concentrating portions of the linin come 
together, and there are striking cases of concentration to be seen, just as in 
the somatic and presynaptic prophases (Figs. 75 and 76). Meanwhile the 
cell-plate has given place to a clear wall which divides the two daughter 
nuclei, and which is continuous at either end with the circular enveloping 
wall (Figs. 75 and 77). The nuclei elongate at right angles to the plane of 
the heterotype spindle (Figs. 75 and 77). At the same time definite spindle 
fibres appear in the cytoplasm (Figs. 75 and 77). They focus more or less 
to a point at either end, and widen out as they approach the extremities of 
the nucleus. Concentration of the segments proceeds. There are still 
small, flat, angled portions of linin, but they tend to become more and 
more individualized (Figs. 75 and 76). They are connected by fine threads. 
Gradually the segments join on one to the other (Fig. 77). Sometimes 
longitudinal fission can be seen in them, but generally they are ribbon-like 
and more or less homogeneous (Fig. 77). At a later spireme stage the 
chromatin contents are drawn out into long strands, which lie in the plane 
of the elongated narrow nucleus. These strands may lie massed together 
and be interwoven so as to form an almost undecipherable tangle. The 
spindle fibres enter the nucleus and penetrate the tangle (Fig. 78). The 
nuclear wall has meanwhile gradually disappeared. 
Metaphase. 
Then the chromosomes become differentiated, and take up their 
position on the equatorial plate (Fig. 79). At first they are still long and, 
lie somewhat in loops and curves (Fig. 78), but when they have completed 
their equatorial arrangement they contract considerably, and consequently 
shorten and straighten (Fig. 79). Their outer ends become bifurcated, and, 
contrary to the direction in the somatic divisions, the split apparently pro¬ 
ceeds inwards. The spindle fibres usually focus to a sharp point at either 
end (Fig. 79). The two nuclei generally (if not always) divide parallel to 
