10 RICHARD ASSHETON AND THOMAS G. STEVENS. 
an unstained section the meandering course of this inter- 
vening layer stands out clearly. 
It may be noticed that so complicated and complete is the 
branching of the foetal plates that a section taken horizontally 
through the region B is but slightly different to one taken 
vertically through the same region. 
In region C of fig. 1 we find a very different state of affairs. 
This region is that bordering upon the line of rupture whereby 
the after-birth has become separated from the walls of the 
uterus. ‘The general character of this layer may be gathered 
from fig. 3. Naturally enough the tissues here show signs of 
damage and are more difficult to interpret. There are, however, 
certain details of considerable interest which can be clearly 
defined. There is a complete absence of the “ meandering” 
appearance. The maternal loop-like channels are not visible 
as such. 
The lobate terminations take the place of the foliation 
described above. ‘These are of much interest. Fig. 12 is a 
drawing of a section through one of these. Compared with a 
foliation it may be noticed that the whole is thicker—there 1s a 
greater amount of fibrous ground tissue—the blood capillaries 
are more internally placed (cf. fig. 2, c.), and are really more of 
the nature of small arteries and venules than true capillaries. 
And, lastly, over the surface of the whole there is a well marked 
layer of almost columnar cells with well marked cell boundaries 
and nucleus. The layer of columnar cells cannot be found 
everywhere as clearly as in the upper part of the fig. 12, but 
traces of it can generally be seen as in the lower surface of 
the villus in fig. 12. 
These villi in some cases seem to have passed through the 
whole of the after-birth and possibly may have become torn 
during parturition, and small portions may have been left 
behind in the uterus. Generally, however, they end as in 
figs. 3 and 12, lying in a loose detritus of cellular tissue. In 
this detritus we detect large numbers of cells which have the 
same general characters as those forming the columnar epi- 
thelium just described. 
