
286 PROFESSOR TURNER ON THE 


best marked in the longitudinal folds. The corpuscles of the connective tissue 
were ovoid and fusiform, relatively large in size and granular. Ramifying 
in the membrane were the small blood-vessels derived from those of the 
chorionic villi, which had been torn through when the grey membrane was 
stripped off ; hence this membrane derived its vascular supply from the chorionic 
and not from the maternal system of blood-vessels, and must be regarded as a 
foetal and not a maternal structure. On that surface of the greyish membrane 
which lay next the non-deciduous mucosa, patches of epithelial cells similar to 
those previously described on the free surface of the mucosa were seen. I 
believe that these cells, though adhering to the membrane, did not properly 
belong to it, but to the mucosa, from which they had separated in peeling off 
the placenta ; and in this manner one may explain why the epithelial covering 
of the mucosa seemed to form an interrupted and not a continuous layer. 
Numerous vertical sections were now made through the entire thickness of 
the placental lobes, and examined with the view of determining the arrangement 
and structure of the villi of the chorion, their more exact connection with the 
greyish layer, and their relations to the intra-lobular parts of the deciduous 
mucosa (fig. 5). The stems of numerous large villi arose at frequent intervals 
from the placental surface of the chorion, and passed through the placental 
lobules almost perpendicular to the plane of the chorion and branched in a 
highly arborescent manner. From the sides of the stems of the villi, from 
the sides of their branches, and from the extremities of the greater num- 
ber of these branches much smaller branched villous processes arose 
which gave origin to multitudes of villous tufts. Some of the larger 
branches from the parent stem had, however, a different mode of termi- 
nation: they reached the periphery of the lobule and blended with the 
ereyish layer already described. This layer, therefore, was obviously formed 
by the junction with each other of the ends of those branches of the villi which 
reached the periphery of the lobule; by their union a continuous layer of foetal 
tissue was formed, not only on the uterine surface of each lobule, but reaching 
for some distance down its sides. From the placental surface of the chorion, in 
the intervals between the origins of the stems of the large arborescent villi, 
numbers of short branching villi arose, which soon subdivided into terminal 
branching tufts. The terminal branching tufts were, as a rule, slender elongated 
structures, but some were shorter and more club-shaped. 
The matrix substance of the villi consisted of a delicate connective tissue 
containing multitudes of distinct corpuscles. Where this tissue formed the 
terminal tufts the corpuscles were very numerous, and appeared in some cases 
not only imbedded in the substance of the tuft, but as if arranged, after the 
manner of an epithelium, on the free surface. In some of my preparations the 
more superficial cells were detached, and were seen to have the form of delicate 


