EXPLANATION OF PLATES I, 2, AND 3. 



PLATE 1. 



FIG. 1. Section through the attachment of the villi to the tube wall in Xo. 109, showing the 

 extension of the trophoblast into the veins, with the destruction of their endothelial 

 lining. X 72. 



FIG. 2. Section through the veins in the tube wall of No. 109, showing a more extensive invasion 

 of trophoblast than in the veins pictured in fig. 1. X 100. 



FIG. 3. Section through an extension of vacuolated syncytium between the tips of the villi and 

 the tube wall (No. 109). At B. V. a blood vessel is tapped and between it and the 

 villus there is an extensive hemorrhage of blood into the spaces of the vacuolated 

 syncytium. X 50. 



I'm. 4. Syncytium covering a typical villus (No. 808). Stained with hematoxylin and aurantia. 

 The blood corpuscles fill the spaces of the syncytium and fragments of corpuscles lie 

 within the protoplasm of the cells. There are all gradations between complete blood 

 corpuscles and granular protoplasm which take on the same color. X 300. 



PLATE 2. 

 FIG. 1. A villus which is undergoing fibrous degeneration (No. 694). X 160. 



FIG. 2. Section through the last remnant of the ovum in apposition with the tube wall (No. 472). 

 The villi have undergone extensive degeneration and the trophoblast and part of the 

 tube wall are hyaline. X 120. 



FIG. 3. Tip of a fibrous villus from No. 670, partly covered with trophobhist, which extends over 

 in the adjacent clot, where it is undergoing hyaline degeneration. All stages of tropho- 

 blast undergoing hyaline degeneration are shown. X 100. 



FIG. 4. Section through a necrotic villus of No. 575 which is covered with an irregular mass of 

 dead epithelium. At points the nuclear mass is clumped and somewhere the necrotic 

 mass radiates between the blood cells. There are also accumulations of leucocytes. 

 X 105. 



FIG. 5. Section through an island of vacuolated syncytium which is extensively infiltrated with 

 leucocytes (No. 567). X 55. 



FIG. 6. Specimen No. 430, showing extreme degeneration of the syncytium. The protoplasm is 

 converted into a hyaline mass and chromatin is represented as nuclear substance. 



FIG. 7. Portion of diagram shown on page 80 (No. 670), enlarged 700 diameters. The invagi- 

 nation of the epithelial cells is very pronounced. There are also numerous large, pro- 

 toplasm cells seen in the spaces of the mesenchyme. These are the so-called Hof- 

 bauer cells. 



PLATE 3. 



FIG. 1. Section through the point of attachment between a fibrous villus and the tube wall of 

 No. 570. The epithelial covering has been detached and the space is filled with blood. 

 X100. 



Fiu. 2. Section through the degenerated ovum in situ (No. 754). The coelom is filled with 

 mottled granular magma into which there are radiating cells of mesenchyme. X 85. 



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