EXPERIMENTAL STUDIES ON FETAL ABSORPTION. 



101 



REFERENCES CITED. 



DOWNEY, H., 1917. Reactions of blood and tissue cells to 

 acid colloidal dyes under experimental con- 

 ditions. Anat. Record, vol. 12, p. 429. 



, 1918. Further studies on the reactions of blood and 



tissue cells to acid colloidal dyes. Anat. 

 Record, vol. 15, p. 103. 



GOLDMANN, E. E., 1909. Die aussere und innere Sekretion 

 des gesunden und kranken Organismus im 

 Lichte der "vitalen Fiirbung." Beitr. z. klin. 

 Chir., vol. 64, p. 192. 



GROSSER, O., 1909. Vergleichende Anatomie und Entwick- 

 lungsgeschichte der Eihaute und der Placenta. 

 Vienna. 



ROMER, A., 1904. Weitere Studien zur Frage der Intrau- 

 terinen und extrauterinen Antitoxintibertrag- 

 ung von der Mutter auf ihre Nachkommen. 

 Beitr. z. exper. Therap., Heft 9. 



WISLOCKI, G. B., 1920. Experimental studies on fetal 

 absorption. I. The vitally stained fetus. 

 II. The behavior of the fetal membranes and 

 placenta of the cat toward colloidal dyes in- 

 jected into the maternal blood-stream. Con- 

 tributions to Embryology, vol. 11, Carnegie 

 Inst. Wash. Pub. 274. 



DESCRIPTION OF PLATE. 



ch. ep., Chorionic epithelium. 



d. ., Decidua serotina. 



ec. endo., Ectoplacental endoderm. 



endo. v., Endodermal villi. 



g. c., Giant cells. 



p. I., Placental labyrinth. 



r. c. e.. Roof of the central excavation. 



s. endo.. Sinus endodermaticus. 



. m., Vitelline membrane. 



Fio. 1. Gross specimen showing appearance of the vitelline membrane and placenta of a fetal guinea-pig, measuring 

 18 mm. after injection of trypan blue into the maternal blood-stream. The deeply stained villous 

 portion of the vitelline membrane is readily distinguishable, as is also the unstained roof of the central 

 excavation. 



FIG. 2. Section through vitelline membrane of guinea-pig at its attachment to the surface of placenta. The char- 

 acter of the epithelium covering the various portions of the vitelline membrane is clearly shown. The 

 endodermal cells clothing the villi are loaded with trypan-blue granules. The curious papillary hyper- 

 plasia of the ectoplacental endoderm is well illustrated. 



Fia. 3. Section through placental labyrinth of guinea-pig, showing tracery of trypan blue in the chorionic epithelium 

 after repeated administration of the dye. 



Fio. 4. Specimen showing distribution of trypan blue in the placenta of guinea-pig after injection of the dye into 

 maternal blood-stream. Note that the only unstained area is the roof of the central excavation. 



FIG. 5. Specimen showing the distribution of trypan blue in the placenta of guinea-pig, after injection of the dye 

 into the fetal circulation. Note that when the dye reaches the placenta through the fetal vessels, the 

 roof of the central excavation becomes stained, but none of the dye diffuses into the decidua. 



Fia. 6. Section through the surface of the placenta of guinea-pig (about the middle of pregnancy) showing the vitally 

 stained giant cells beneath the ectoplacental endoderm. 



Fia. 7. Section of the placental labyrinth of guinea-pig showing polymorphonuclear leucocytes containing granules of 

 trypan blue. 



Fio. 8. Section through the vitelline membrane of the rabbit, showipg the columnar cells covering the villi filled with 

 granules of trypan blue. 



Fia. 9. Section from labyrinth of rabbit's placenta, showing syncytium in which numerous tiny granules of trypan blue 

 are visible. 



