330 Dr Duckworth, A critical description of three cases 
The phenomenon of a single umbilical artery, arising as this 
one does from the more anterior portion of the abdominal aorta is 
evidently quite distinct from that observed in specimen A, as is 
shewn by a comparison of Fig. 6 with Fig. 1. 
The interpretation of the anomaly in specimen E is rendered 
clearer by the study of specimen F, to which attention is now 
directed. 
III. In bulk, specimen F (Plate xiii, Figs. 7, 8, 9) corresponds 
to the normal average human foetus at the ninth month. The 
sex is female. From vertex to coccyx the length is 280 mm., and 
from vertex to heel 447 mm. After some weeks’ immersion in a 
mixture of alcohol and formalin, the specimen weighed 2800 gm. 
The dimensions of the head are as follows: length 113 mm.: 
breadth 90 mm.: circumference 332 mm. 
The head, neck, upper limbs and the upper part of the torso 
generally, are not deformed. A very distinct musculus sternalis is 
present on the right side. 
The lower limbs are conjoined from the hips to the ankles: 
the soles of the feet are inverted, and the feet diverge anteriorly. 
A skiagram shews that the skeleton of each lower limb has been 
formed even where the softer overlying tissues are joined. 
From the abdomen an umbilical hernia protrudes. The 
contents of the sac are as follows : 
(a) about 4 in. of the small intestine with a distinct and 
free Meckel’s diverticulum ; 
(b) part of the quadrate lobe of the liver, which is very 
curiously prolonged to reach this position ; 
. (c) the umbilical vein, a single umbilical artery and the 
urachus (Fig. 10) in which a lumen (still lined with 
epithelium) is conspicuous in transverse sections. 
Fig. 10. Transverse section ( x 8) of the urachus (on the left) and the single 
umbilical artery (to the right of the drawing) in specimen F. 
From the lower aspect of the hernia the umbilical cord 
(Fig. 11) arises and is found to contain the structures enumerated 
in (c) above. 
