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it is interesting to note, that yolk lies outside of both of these portions. 
At two points of the ventral wall — in some sections only at one — 
the merocytic layer is raised up in the form of a hillock projecting 
into the lumen of the gut. One of these hillocks, though like its 
fellow in composition, is insignificant in size, the other is composed 
of a conical heap of yolk-laden merocytes. At the surface of the yolk, 
between it and the merocytic layer of the gut, is a region, in which 
there is not much yolk, a region made up of a protoplasmic reticulum, 
or plasmodium !), as it might aptly be termed, of the merocytes, and 
this network or plasmodium stretches into the superficial portion of 
the yolk. By this network, as is made out with ease, yolk-plates 
are drawn to the merocytes and taken in or engulfed by them ”). 
Within the merocytes the yolk-plates are broken up, and, perhaps, to 
a greater or less degree emulsified, and this is probably effected to 
a large extent by the chromatin of the nucleus. This latter has under- 
gone great degeneration, and is represented by a number of small 
rounded deeply staining bodies. Often the broken up yolk-plates ?) 
form an aggregation in the neighbourhord of one or more of these 
minute nuclear particles. 
The centre of the gut is occupied by a mass of more or less 
emulsified yolk (a very few large plates, a great number of very small 
ones, and a large quantity of finely divided yolk), with numbers of 
minute nuclei scattered in the mass. To the right side, next the 
thickened portion of the embryonic or permanent gut, this mass con- 
sists of very fine particles. 
How came the mass there, and how arose the nuclear fragments 
within it? 
It may be noted, that here and there in the mass there is a mero- 
cyte, charged with emulsified yolk and containing numerous minute 
and degenerate chromatin-bodies, which has not yet fallen to pieces. 
And it is not difficult to demonstrate, that, as fast as the merocytes 
1) A network of this kind, but smaller in dimensions, is often formed 
by single merocytes of Scyllium, when they are actively attacking the yolk. 
2) There are, indeed, drawings extant (ve. g. by Rickerr and VircHow) 
showing a protoplasmic layer around the nucleus of the merocyte, but 
usually the merocytes are spoken of, as though they were naked nuclei 
free from protoplasm. This appears very frequently to be the case, but 
my observations lead me to conclude that the merocytes can form a 
protoplasmic body around themselves when that is needed. 
3) The large yolk-plates of Lepidosteus, when thus broken up within 
merocytes, retain, unless they are very minute, the shape of the unbroken 
plates, 1. e. they are ovoid. 
