564 
J. BRONTE OATENBY. 
absolute and xylol. They are embedded as usual, cut into 
6 fx sections, and stained in iron alum haematoxylin by the 
long method. 1 These sections are carefully differentiated, and 
then tinged with orange G. or van Giesen. The mitochoudria 
and Nebenkern are intense black and beautifully clear. 
Neither Benda’s, Bensely’s, nor any of the other coloured 
stains approach such preparations for definition, and for the 
detail which is shown. As will be explained in another part 
of this series, iron haematoxylin is not always indicated for 
mitochondrial work, Bensely’s acid fuchsin having been found 
better for some objects. 
The Flemming solution, in which the acetic acid is sub- 
stituted by nitric acid of 3 per cent., gives a very intense 
stain when used on the mitochondria. 
The Germinal Epithelium. 
The germinal epithelium in its indifferent condition consists 
of a row of flattened cells containing compressed nuclei. The 
epithelium is not a syncytium, as has been stated by some 
authors. In PI. 30, fig. 2, is drawn at a very high power 
three cells of the epithelium in an indifferent state. The 
nucleus is an oval, flattened structure, and as it is here cut 
in its narrowest way it looks elongate. The chromatin is 
arranged in a large number of irregularly triangular lumps, 
which here and there are intercommunicating. The cyto- 
plasm is not very large in volume, and consists of a wide 
reticulum, which in some cases can be seen to be condensed 
into a dark mass near one edge of the nucleus (see PL 30, 
fig. 2, PI. 31, fig. 20, etc.). 
The cells of the germinal epithelium rest upon a fibrous 
layer, shown by Ancel to be of mesodermal origin (PI. 30, 
figs. 2, 3, and 4, A.L.N., etc.). This layer contains nuclei, 
which vary in size very greatly. In PI. 30, figs. 3 and 4, are 
drawn quite typical examples of the germinal epithelium. 
The germinal epithelial cells ( Gr.E .) are seen resting between 
1 Ivon alum ten to twelve hours, hsematoxylin twelve to fourteen 
hours. 
