388 MINOT. [Vou. II. 
inders, Cut 8, A, each one with a rounded top, in which is sit- 
uated the more or less nearly spherical nucleus; sometimes, 
however, the nuclei lie deeper down. Less frequently the 
epithelium is thin, Cut 8, B, and its nuclei, which are trans- 
versely elongated, lie further apart. It is probable that these 
differences are not structural, but conditional upon the greater 
or less degree to which the amnion is stretched. I have ob- 
served no constant differences between the placental and the 
remaining amnion. The most interesting peculiarity of the 
epithelium is best seen in surface views; namely, the inter- 
cellular bridges. They display themselves with a clearness 
which I have never seen in other epithelia; see Cut 11. 
The nuclei, z#, are relatively large, rounded with distinct out- 
lines; they have a more or less well marked intra-nuclear net- 
work, with thickened nodes, and a small number of deeply 
stained granules, which are probably chromatine. Each nucleus 
is surrounded by a cell body, f/; and the adjacent cell bodies 
are separated from one another by clear spaces. With high 
powers, as represented in the cut, one sees that these spaces are 
separated from one another by threads of material, pv, stretch- 
ing across as bridges, connecting neighboring cells. Examined 
attentively, the protoplasm of the cells exhibits a vacuolated 
appearance. One is thus led to view the epithelium as a sponge 
work of protoplasm somewhat condensed around each nucleus ; 
according to this interpretation the intercellular spaces are large 
meshes of the sponge work, and the intercellular bridges are 
protoplasmic. A recent paper! by M. Manille Ide, which I owe 
to the kindness of the author, brings a series of interesting ob- 
servations to show that the intercellular bridges of the Rete 
Malpighi of the mammalian epidermis are not protoplasmic, but 
processes of the cell membranes. This paper has led me to re- 
examine my preparations of the amniotic epithelium, but I have 
been unable to find in them any indications of membranes 
around the cells or reasons for considering the intercellular 
bridges as other than protoplasmatic in constitution. Whether 
this result is due to the imperfection of my preparations, or is 
in accordance with the truth, must be decided by further inves- 
tigation. 
1 Manille Ide, La membrane des cellples du corps muqueux de Malpighi. Za 
Cellule, 1V., 2me fasc., 1888. 
