152 



THE PHYSIOLOGY OF TWINNING 



2. Acardii acormi, which possess only the head and 

 the merest rudiments of body and extremities (Fig. 52). 



Fig. 52. — A bizarre type of heartless human one-egg twin, which had 

 a nearly normal partner, born alive (see severed placenta of the latter 

 turned to the left). This monster is technically an acardius acormus 

 (heartless, trunkless). It is little more than a large head attached 

 to the placenta by an umbilical cord. Such a monster is kept alive by 

 borrowing blood from its more fortunate twin partner. (After Schatz.) 



