338 



HUMAN UTERUS AND F(ETAL APPENDAGES. 



or cotyledonary surface; its smooth, amniotic surface faces the cavity in which 

 the foetus lies. 



A more detailed examination of the gross appearance of a placenta dis- 

 charged at term leads to the following additional observations : The color is a 

 reddish or purplish gray, varying in tint according to the condition of the blood, 



FIG. 196. HUMAN PLACENTA AT FULL TERM, DOUBLY INJECTED TO SHOW THE SUPERFICIAL DISTRIBU- 

 TION OF THE BLOOD-VESSELS. 

 The veins are drawn dark and lie deeper than the arteries. One-half natural size. 



and mottled between the divaricating blood-vessels by patches and networks of 

 pale yellowish or flesh color. The light pattern is produced by the tissue of the 

 villi shining through the membrane of the chorion. These appearances are less 

 distinct when the placenta, as is usually the case, is covered by the thin amnion. 



