EXPLANATION OF FIGURES. 



Plate I. Fig. 1. The pregnant uterus split up its anterior wall. The light spot 

 marked "ovum" denotes the site of embedding of the ovum. o. i.= 

 Internal Os. 



Fig. 2. Three microscopic sections demonstrating the mucous membrane 

 elevation (h), in which the ovum lies, g line of separation of 

 mucosa and musctilaris. 2a Section 5; 2b~ Section 80; 2c 

 = Section 160. (Natural size.) 



Plate II. Fig. 3. Section 4. Outer border of the mucous membrane elevation, e = 

 surface epithelium, v = decidua vera. d Dilated and folded gland, 

 showing beautifully preserved epithelium, c Capillaries. F 

 Mucous membrane furrow. Obj. A A. Oc. 3. 



Fig. 4. Section 10. fi = Fibrin cover, e = Rests of surface epithelium, c 

 = Confluent blood vessels. F = Furrow, tr = Trophoblast pro- 

 cesses, sy = Syncytial cells. Obj. A A. Oc. 3. 



Plate III. Fig. 5. Section 15. Obj. AA. Oc. 12. 



fi = Fibrin cover. 



w = Rests of cubodial epithelium on the fibrin cover. 



e = Underlying surface epithelium (?). 



e.s. = The same depressed, simulating a gland opening. (See 

 Text!). 



c = Confluent blood spaces. 

 Fig. 6. Section 19. Obj. A A. Comp. Oc. 4. 



fi = Fibrin cover. 



e.s. Trace of depression as seen more plainly in Fig. 5. 

 (Section 15). 



c = Confluent blood spaces. 



tr = Trophoblast processes. 



F Mucous membrane furrow. Red blood corpuscles between 

 the depression, (e. s.) and fibrin cover. 



Plate IV. Fig. 7. Section 22. .Obj. A A. Oc. 3. 



fi = Fibrin cover. 



e From the edges surface epithelium ( ?) is seen passing 

 beneath the fibrin cover. Possibly syncytium. 



d.v.= Decidua vera. 



c = Confluent blood vessels. 



tr = Trophoblast processes. 



F = Mucous membrane furrow. 



"ovum" = The Fianlage, laterally cut, is seen for the first time. 

 Fig. 8. Section 27. Obj. A A. Comp. Oc. 4." 



fi = Fibrin cover. To the right arranged in folds. 



d.v.^ Decidua vera. 



c Confluent blood vessels. 



F = Mucous membrane furrow. 



dr = Glands. 



tr Several trophoblast processes have become anchored in 

 the periphery of the mucous membrane. 



sy = A plug with knob-like syncytial processes. 



"ovum".= Eianlage becomes more distinct. 



Plate V. Fig. 9. Section 26-28. Zeiss Obj. A A. Oc. 3. 



fi = Fibrin cover. To the right arranged in folds. 

 e = Border epithelium (?), passing from surface under fibrin 

 cover. Probably a band of syncytium passing from tropho- 

 blast (tr). 

 tr = Trophoblast processes. 



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