File:Wislocki1920 plate 4.jpg

Fig. 13. Cat fetus measuring 6.8 cm surrounded by enraptured membranes

Showing the coloration of the placenta and chorion after repeated injection of trypan-blue into the maternal circulation. Note that the chorion over the poles of the fetus is unstained. The allantoic and amniotic fluids do not contain a trace of dye and the fetus is unstained.

Fig. 14. Placenta of cat nearly full term

After repeated injection of trypan-blue into the maternal blood stream, showing the distribution of dye in the chorionic epithelium.

Fig. 15. Placenta of a vitally stained cat nearly full term

Showing several multimiclear giant cells of the chorionic ectoderm filled with particles of trypan-blue.

Fig. 16. Section of the "brown border" of the placenta of a cat

Nearly full term, showing the absorption of erythrocytes and of trypan-blue by the chorionic epithelium.