761 
of Edinburgh, Session 1871-72. 
Der Kolk, Arthur Farre, and Ercolani regarding to the relations of 
the maternal blood-vessels to the placenta and chorionic villi. He 
then proceeded to state the results of his own observations on various 
specimens of placentae, some of which had been separated at the 
full time, others prematurely, and on three specimens attached to 
the uterine wall. Two of these latter were from women at or 
about the full period of gestation, whilst the third was from a 
woman who died undelivered in the sixth month of pregnancy. In 
one of the attached specimens a pipe had been introduced into a 
uterine vein in the broad ligament, and a coloured gelatine in- 
jection had been passed along the venous sinuses in the muscular 
wall, and the utero-placental veins into the placenta. The utero- 
placental veins were followed through the decidua serotina, and were 
seen to pierce the uterine surface of the placenta. The walls of 
these veins were so delicate that they tore through on the appli- 
cation of very slight force. Thin sections made through the 
placenta and the adjacent part of the uterine wall permitted the 
author to trace a direct continuity of the injection within the 
placenta with that within the utero-placental veins and uterine 
sinuses, and showed the one to be continuous with the other. The 
injection also passed into veins of considerable size, situated within 
the decidua reflexa, near the attached border of the placenta. 
In another attached specimen, the intra-placental sinus system 
was injected with coloured gelatine from a pipe inserted into one 
of the uterine arteries, and the injection of the system of inter- 
communicating spaces within the placenta was as readily made as 
in the specimen where the injection was passed through the uterine 
vein. In the third attached specimen, the injecting pipe was 
introduced into the cut face of a section through the placenta itself, 
and the intra-placental sinus system was not only distended, but 
some of the injection had even entered the utero-placental veins. 
Thin sections of the injected placentse had been made and ex- 
amined both with low and high powers of the microscope. Draw- 
ings, greatly enlarged, of the appearances seen on examining these 
sections were shown to the Society, and the author pointed out that 
these were to be regarded as actual representations of the objects, 
and not, as had previously been almost universally the case, mere 
diagrammatic conceptions of what the anatomist might consider to 
