362 MINOT. [Vou. II. 
authors examined late stages when the fissure is completely 
filled by connective tissue, so that there is no space —a condi- 
tion found in the rabbit at thirteen days. It will be convenient 
to designate the structure as the swb-placenta. Its occurrence is 
confined to rodents so far as at present known. Finally, we 
have to note that at the edge of the placenta, toward the peri-pla- 
centa, the sub-glandular layer, which we are now considering, is 
characterized by the presence of deeply stained fragments of 
glandular epithelium irregularly scattered through the other 
tissues and similar in appearance to the remnants of the glands 
about the sub-placenta. These fragments appear to have been 
seen by Ercolani, Creighton, Masquelin, Swaen, and others, and 
variously interpreted, their true nature not being recognized. 
The disappearance of the glands at the centre and at the 
_ periphery of the placenta virtually increases the domain of 
the sub-glandular layer. The greatest changes have occurred 
in the glandular layer. Scarcely a trace of the perivascular cells 
can be found; the space they formerly occupied is taken up by 
a very loose embryonic tissue; the glands are completely altered ; 
they have lost their special affinity for eosine and cochineal, 
neither the hyaline substance of which they are composed nor 
the nuclei they contain being more stained than other tissues 
(compare Fig. 8); they are irregularly cylindrical in shape, very 
much contorted, and united with one another at irregular inter- 
vals, so as to constitute an actual network: they are very much 
vacuolated; their deep portions (fundi) are somewhat wider than 
the upper parts; here and there one sees a remnant of the origi- 
nal central lumen. The contorted masses, which I consider 
glands, are apparently the same as have been seen by Mauthner 
in the placenta at term, 115, p. 121. He describes these cords 
as consisting of the fused epithelium of adjacent foetal villi, and 
the spaces I have designated as vacuoles he describes as maternal 
blood-channels; he states explicitly that he has injected them 
from the maternal vessels, and in other cases found them gorged 
with maternal blood. These statements are irreconcilable with 
my own views, detailed in the present article. The uterine epi- 
thelium has entirely disappeared both from the top and the sides 
of the placenta. The top surface is covered by a very thin layer 
of flat epithelium, Fig. 8, sth, which is found, when followed 
out, to be continuous with the lining of the body cavity of the 
