1154 



PROF. J. P. HILL AND MR. R. H. BURNE ON THE 



From the dorsal margin of the main cavity three accessory lobes 

 stretch across t])e left aspect of the foetus (text-fig. 2 and PI. II. 

 fig. 2) : (a) a posterior lobe that runs caudally nearly to the mid- 

 line of the amniotic sac ; (b) a dorsal lobe that covers the flank 

 and sacral regions of the foetus and extends for a short distance 

 beyond the dorsal mid-line ; (c) a cephalic lobe, of sausage-shape, 

 that passes directly towards the head of the foetus across the 

 shoulder as far as the root of the left ear. At the base of this 

 lobe is a small ventrally directed subsidiary pocket. 



Text-figures 2 & 3. 



Spec. A, from left and riglit sides respectively', of foetus, after removal of chorion, 

 to show the main and accessory lohes of allantois. 



The cephalic margin of the main cavity gives rise to but one 

 lobule (d), an extensive finger-shaped sac folded back upon itself 

 in the form, roughly, of a Y. The sac runs at first cephalad 

 across the left eye of the foetus, and then is reflected round the 

 cephalic pole of the amniotic sac, giving off at its fui-thest point 

 a blunt conical process (the tail of the Y) that extends into the 

 similarly shaped prolongation of the chorionic sac that occupies 

 the cervix uteri. After thus curving round the cephalic pole of 

 the amnion, the lobule d passes caudad along the dorsal surface 



