No. 3-] UTERUS AND EMBRYO. I 
37 
The ob-placenta, 04.p/, shows everywhere a marked growth of 
its glands; as illustrated by Fig. 10, the glands are follicular ; 
their cavities wide. The glands are not branched or pouched, 
as the appearances in the sections suggest; they are broad 
tubes closely packed, and are necessarily cut obliquely in most 
cases. The rather ragged-looking epithelium is composed of 
long cylinder cells (Fig. 10), with the nuclei at various heights, 
and the protoplasm a good deal colored by the cochineal. The 
connective tissue of the mucosa has also grown, and forms both 
thin inter-glandular dissepiments and a thickened sub-glandular 
stratum. In the centre of the ob-placenta the mucosa is still 
further thickened to make room for the monster cells, which lie 
for the most part below the glands, but are found also between 
the glands and in the superficial portion of the muscularis. At 
one point the ob-placenta is interrupted by a protuberant mass, 
4, resembling the peri-placenta in structure; it consists of 
crowded perivascular cells with dilated blood-vessels, and is cov- 
ered by epithelium. As I have seen nothing analogous to this 
mass in any other specimen of any age, it must be regarded as 
a singular sporadic variation from the normal processes of devel- 
opment. 
The origin of the monster cells I am inclined to seek in the 
uterine epithelium, as stated in § 7. The appearance of their 
cell bodies, and of their nuclei at once suggest this origin on 
account of the similarity with the appearance of the degenerated 
epithelium elsewhere. We find, also, the smallest monster cells 
near the epithelium. In Fig. 11 portions of the epithelium of 
the peri-placenta are represented. The cells are all multinucleate, 
as seen both in vertical section, A, and surface views, B; occa- 
sionally, but very rarely, there is a cell with the nuclei gathered 
together in a central mass, with an indistinct line enclosing the 
bunch, Fig. 11, ¢. These cells are larger than the rest, and their 
protoplasm is somewhat degenerated. If such acell were to de- 
tach itself, and hypertrophy and the bunch of nuclei to break 
down, it would resemble a monster cell. Yet I can find no evi- 
dence that such a metamorphosis actually takes place in the 
ob-placenta. In the ob-placenta itself there appear a few epithe- 
lial cells with a single nucleus which are slightly enlarged, and 
are possibly the initial stages of monster cells, but between 
them and the youngest monster cells observed I have failed te 
