197 



Fig. 30. Disintegration of the maternal glycogenic tissue from a placenta 

 of about the same age as that figured in Fig. 5. 

 The smal! cytoplasmic granules may be seen both in one of the 

 glycogen cells and also adhering to the supporting cells. 

 (Aceto-corrosive). 

 Fig. 31. Last stage in the degeneration of this tissue, from the placenta 

 represented in Figs. 6 and 11. 



One glycogen cell is shown containing granules; granular débris 

 is scattered over the supporting cells. 

 (Aceto-corrosive). 

 Fig. 32. Maternal glycogen cells; 



a. As observed fresh; note the single nucleolus in the nucleus, the 



granules in the cytoplasm, and the vacuoles. 

 h, Flemming preparation; observe the same characters. 

 c. Foa. A dense area of cytoplasm may be seen to one side of the 



nucleus. 

 (h Flemming. A glycogen cell breaking up, and its granules dis- 

 persing; below is the nucleus. 

 Fig. 33. Three stages in the glycogenesis of trophoblast cells. 



a. From the deep layer; mitoses are seen. 



b. Nearer the upper side; vacuolation is beginning. 



c. From the upper side; the cell is full of glycogen. 



The shape of the nuclei, and the nucleoli may be noticed. 



From the preparation represented in Fig. 6 ; the figures are taken 



from the proness of the glycogenic trophoblast which dips down 



into the allantoic portion. 

 (Aceto-corrosive). 

 Fig. 34. Trophoblastic glycogen cells. 



Fig. 35. Pseudo-endothelial cells lining a trophoblastic sinus. 

 Fig. 36. A small part of the allantoic portion of the trophoblast; from the 



placenta figured in Fig. 5. 



The trophoblastic laCunae are irregular in shape and often crossed 



by strands of cytoplasm. 



A patch of cytotrophoblast is shown on the right. The allantoic 



capillaries are lined by a defmite endothelium and surrounded by 



connective tissue. 

 (Foa). 

 Fig. 37. Section across the capillaries and lacunae, from a placenta at the 



end of gestation. 



The embryonic blood corpuscles (no longer nucleated) are contained 



in exceedingly thin walled capillaries. These are not surrounded 



by connective tissue but abut directly on the trophoblast. The 



latter is thinner than before, but the nuclei are still rounded. 

 (Foa). 

 Fig. 38. From a placenta of sixteen days. 



Trophoblast from the allantoic region with fat globules. 

 (Flemming). 



