PLATE 5 



EXPLANATION OF FIGURES 



Photogra])h of a specimen delivered by Dr. Frank Erdwurm of New ^'ork. 

 A living female child was attached to the cord leading away from the upper 

 placenta. This baby was enclosed within its own chorion, the upper membranes 

 shown in the picture. The tw'o fetuses of about six months' development shown 

 below were enclosed in a common chorion and their cords are attached to a com- 

 mon placenta. These are identical twin girls. About three months 'before 

 birth their cords became so twisted that the i)lacental circulation was cut off 

 and they died. The mother was disturbed for a time until the uterine situa- 

 tion became adjusted and this ])lacenta shunted off. The fetuses remained 

 enclosed within their membranous sac and at birth were considerably shriveled 

 and somewhat macerated. 



Probably the implantation of the single individual in some way delayed im- 

 plantation of the other placenta and caused the arrest which resulted in the 

 .twinning of the second egg. 



274 



