302 
Dr Duckworth, The histology of the 
Now through many sections (45 in number) the uterine 
epithelium beneath the blastocyst remains intact. Such a con- 
dition is clearly shewn in Fig. 4 representing section No. 45. 
In this section (Fig. 4), the coast-line, so to speak, of the 
uterus is still clothed with epithelial cells, and the blastocyst 
is still some distance away, looking like a number of islands 
separated from the coast by a channel. 
But already the effect of the presence of the blastocyst is being 
felt by the uterine tissues. In the sections, only the so-called 
Decidua compacta is shewn, and in this much oedema is present. 
In places in the submucous layer, fibrinous exudation is clearly 
seen (Fig. 4) and as the sections are followed towards the 
more central region, the exudation increases and eventually the 
tension is sufficient to lift the epithelial layer off in strips. The 
process is exactly comparable to that which follows when in acute 
inflammation a submucous surface is denuded while the cast-ofl 
epithelium with detritus and leucocytes forms a so-called “ false 
membrane.” 
By the time this removal has taken place, the blastocyst wall 
is in close apposition with the tissue removed, and the blastocyst 
may very possibly have played a more direct part in its removal, 
than the indirect action it exerts by causing the inflammatory 
exudation. But the appearances seem to fully justify the pre- 
ceding description. 
I must guard this description however from the possible 
inference that the blastocyst is actually attached first to an area 
denuded of uterine epithelium. Most probably at the first 
moment of contact, the epithelial layer is just becoming detached 
as described. 
The detached cells then disappear, and seem to be destroyed 
partly by extravasated blood-cells, but also possibly by the 
embryonic cells now close upon them. 
In two or three sections (46, 47, 48) there are suggestions of 
some proliferation of the uterine epithelial cells over a very small 
extent of surface, but the cells thus characterised cannot be traced 
into contact with any other cells on their exposed aspect, and seem 
rather to be degenerating than increasing. But this occurrence 
demands special mention, for otherwise the very definite statements 
of Selcnka concerning the increase and proliferation of the uterine 
epithelial cells would find absolutely no support at all from the 
present observations. These remarks on the appearances of the 
uterine wall naturally lead to the next division of the subject 
which will be now considered. 
