18 RICHARD ASSHETON AND THOMAS G. STEVENS. 
specimen which resemble the lateral zones. The ragged 
state is due to the projection of villous tufts (V”) of long 
stalks ending in tufts of villi (V”), of similar stalks apparently 
broken (st.v.), and of very occasional large blood-vessels, which 
can hardly, from their nature, be anything else than maternal 
arteries. 
On the face of the section the branching fcetal trunks, and 
the larger blood channels which contain the maternal blood 
can be easily seen; and a more careful inspection will show 
that the smooth zones forming the sides of the placental belt 
are formed by a thin homogeneous material which seems to 
prevent as yet the foetal villi gaining access to the maternal 
tissues along these areas, This material extends across the 
central zone, but is here broken up by the penetration of 
the villi (which no doubt fitted into corresponding crypts in 
the walls of the uterus), and constitutes our region C in 
the description of the full-term placenta. 
The microscopic examination of this smooth area throws 
a flood of light upon what we have found in the full-term 
placenta if, as we think, the edges of the zonary belt repre- 
sent younger phases of development than the more central 
part, which resembles so closely our full-term specimen. It 
will be remembered that these smooth bands are not present 
in the full-term placenta (Chapman, 3, Beddard, 2). 
The nature and origin of the homogeneous material forming 
the smooth surfaces of the lateral bands present us with a 
problem of much difficulty. Probably it is impossible to 
solve it completely in the absence of the uterine part of the 
placenta. There would seem to be two layers—one, the 
thinner, lying next the uterus, in which, or more often on the 
outside of which, we can find a few large rounded cells with 
small, dark nucleus (figs. 19 and 20) ; and the other a thicker 
layer which generally stains very slightly differently from 
the thin layer, and contains more or less degenerated nuclei 
(fig. 23). 
Abutting upon, and in many cases embedded in, this are 
the ends of fcetal villi. These foetal terminations form a 
