PHYSIOLOGY. 35 
abdomen of the foetus at the umbilical opening, and 
then passes backwards to join the anterior extremity of 
the bladder, with the cavity of which the space between 
the two layers of the allantois is in communication. It 
is believed that the allantoid sac or cavity acts the 
aS 
i ee 
a 
Fic. 16. 
Fa:TAL MEMBRANES OF THE Cow AT MID-TERM. 
A, Uterus opened on its left side; B, B, Cotyledons of the Uterus; GG, 
Placentulz; D, D, Allantois; E, Vesicle of the Urachus; F, Amnion; 
G, Umbilical Cord. 
part of a urinary reservoir during foetal life. The 
constricted portion, which passes in at the umbilical 
opening, has been called the “urachus.” 
