FCETAL MEMBRANES. 



593 



accepted facts, referring the student to special articles on the subject for further 

 details. 



In the fully developed placenta, the chorionic villi lie either free (floating 



villi) or attached to the decidua (fastening villi) in what are known as inter- 

 villous spaces (Fig. 500). In sections the villi are, on account of their structure, 



