1070 REPORT—1885. 
That this is a stage of the nucleus is shown not only by the distinctive staining, 
but by the well defined nuclear area, the size of the latter and its relations to 
characteristic accumulations of pigment. In this stage the yolk tablets in the 
nuclear area are of the same size as those of the surrounding yolk substance of 
the segments, 2ndly. A diffuse granular nucleus, in which in the carmine-stained 
nuclear area there are imbedded minute yolk tablets smaller than those in the 
surrounding segment; and also frequently pigment granules. 8rdly. The homo- 
geneous nucleus in which the nuclear substance stains homogeneously in carmine, 
It has distinct boundaries and contains neither yolk tablets nor pigment. 4thly: 
The shrunk nucleus in which a crescent-shaped shrivelled homogeneous substance 
represents the nucleus. The shrunk nucleus may occupy a small part of a hole 
which equals in area the usual size of a homogeneous nucleus. 5thly. Simple 
holes are found which from their size and relations to pigment correspond to the 
position of nuclei. Near these holes one or more tablet nuclei or granular nuclei 
are found in the segment. 
Although the nuclei are generally found round, yet they are frequently found 
in various other shapes in the sections, for example, as narrow strips or as club- 
shaped and crescentic bodies, 
The nucleus is sometimes found homogeneous at one part, and in the condition 
of the tablet or diffused granular nucleus at another, the granular or tablet 
condition being on the periphery of a round, or at the extremity of a fan-shaped 
nucleus. 
The nucleus may be in direct contact with the substance of the segment, or 
may be separated from it by a perinuclear area. The perinuclear area may consist 
of minute breaking down yolk tablets, or may be constituted by a space filled 
with a homogeneous unformed substance, which does not stain in carmine, and 
which contains neither yolk tablets nor pigment. 
Division of the Nucleus—An elongated nucleus may be found divided trans- 
versely by a narrow line which is either unpigmented or contains pigment. This 
line may only partially extend through the nucleus. More frequently two nuclear 
areas are found connected by traces of carmine-stained nuclear substance sprinkled 
amongst the yolk tablets of the segment. Sometimes two tablets or granular 
nuclei, removed to a considerable distance from each other, are found linked by 
this carmine-stained substance. Frequently two such nuclear areas are found in 
an undivided segment without any such connecting link. Less frequently, two 
homogeneous nuclei are found close together in a space which is free from yolk 
substance or pigment; more than two newly formed nuclei may be found in a 
segment, three and even four being occasionally found. The nuclei may be com- 
pletely divided and removed from each other before there is any trace of division 
of the segment. 
Pigment.—There is a well-defined relation between accumulations of pigment 
and division of the nucleus. Pigment is found mixed with minute tablets in the 
granular nucleus. It may penetrate into the interior of a tablet nucleus in a fine 
line. In the other stages it is not found within the nucleus, but is found external 
to it, either in immediate apposition or separated from it by a perinuclear area. 
Pigment tracks may be traced directly from the periphery of the ovum to nuclei. 
Pigment in relation to the Segments.—Pigment is found either equally diffused 
or collected in masses, or forming distinct rings, or around holes within the seg- 
ments. Between the segments it may be found either as a single slender dividing 
line, or as a line which is split at intervals by a space, or it may traverse the 
seements in various directions in lines. ; 
If, as may be taken for granted, the pigment itself is passive in the assumption 
of these forms, then its distribution indicates currents within the segment which 
have a special relation to the nucleus. These currents it is thus shown penetrate 
from the periphery to the nuclei, and in the tablet and granular stages they 
penetrate the substance of the nucleus. The accumulation of pigment around and 
outside the perinuclear area, and its disappearance from the nucleus, indicates a 
centrifugal current. There are thus in the segments both centripetal and centri- 
fugal currents of which the nucleus is a centre. 
