THE PLACENTA. 

 FIG. 257. 



665 



Series of diagrams representing the relationship of the decidua to the ovum at differ- 

 ent periods. The decidua are colored black, and the ovum is shaded transversely. In 4 

 and 5 the vascular processes of the chorion are figured (copied from Dalton). 1. Ovum 

 entering the congested mucous membrane of the fund us decidua serotina. 2. Decidua 

 reflexa growing round the ovum. 3. Completion of the decidua around the ovum. 4. 

 General growth of villi of the chorion. 5. Special growth of villi at placental attach- 

 ment, and atrophy of the rest. 

 56 



