AN EARLY HUMAN OVUM IMBEDDED IN THE DECIDUA 
HISTORY OF THE SPECIMEN 
The ovum was found by Dr. Teacher in a portion of membrane sent to 
him for examination by Dr. T. Douglas Brown, in a mixture of urine 
and blood-clot. The membrane had been expelled by a young woman 
who had been married for about two years, but who had not before been 
pregnant. Dr. Brown recognised a portion of fawn-coloured membrane 
among the blood-clots, which he considered to be probably a portion of 
the decidua of pregnancy, as the patient had passed the date on which 
menstruation was expected by about ten days. By the time the 
specimen reached Dr. Teacher the haemoglobin had diffused out of the 
clots, and the membrane was no longer distinguishable from them. In 
order to differentiate the tissue from the clot, about one-third of its 
volume of 90% alcohol was added to the fluid, and an hour later 
the mixture was decanted and fresh 30% alcohol substituted. Two hours 
later, on examining the material in a white porcelain dish, the mem¬ 
brane was readily identified by its somewhat lighter colour. It was 
roughly quadrilateral in shape, and somewhat broader at one end, 
measuring 3'8 cm. in length and 2 cm. in breadth. It represented 
the greater part, if not the whole of the mucous membrane of one 
wall, probably the posterior wall, of the uterus. It presented the char¬ 
acters of decidua and was mapped out into areas by shallow furrows. Its 
outer surface had the characteristic appearances of the detached surface of 
shed decidua. 
The margin was in parts rather thick and rounded, in other parts 
it faded off into very thin shreds. One of the areas near its centre stood 
B 
