LIST OF ILLUSTRATIONS. 



Fio. 1. Cross-section of twin hydatiform chorionic vesi- 

 cles within the tube. (Specimen No. 825.) 

 X3. 



Fio. 2. Hydatiform villi from same specimen in sec- 

 tion. X 45. 



FIQ. 3. Embryo No. 1771, covered with magma. X 4. 



Fio. 4. Cross-section of tube No. 1771. X 2. 



Fia. 5. Cross-section of tube from same case. X 4. 



FIG. 6. Hydatiform villi from same case. X 45. 



FIG. 7. Hydatiform chorionic vesicle in loco with the 

 tube incised. No. 2052. X 2. 



FIG. 8. Gross appearance of specimen No. 70. XI. 6. 



FIG. 9. Gross appearance of specimen No. 323. X 1.75. 



FIG. 10. Gross appearance of specimen No. 749. X 1.1. 



FIG. 11. Gross appearance of specimen No. 1323. X 1.2. 



FIG. 12. Gross appearance of specimen No. 1325. X 1.2. 



FIG. 13. Gross appearance of specimen No. 1914. X j. 



FIG. 14. External appearance of the larger part of the 

 small mass of specimen No. 1926. X 4. 



FIG. 15. Embryonic (cyemic) mass accompanying No. 

 1926. X 4. 



FIG. 16. A small portion of specimen No. 1189 still in 

 loco. X 6. 



FIG. 17. Another portion of the same specimen. X 30. 



FIG. 18. No. 2077, an apparently normal specimen, 

 partly surrounded by decidua. Natural size. 



FIG. 19. A portion of the above clearly showing numer- 

 ous typical hydatid cysts in area in focus. 

 X3. 



FIG. 20. Sections of villi from specimen No. 690. X 50. 



FIG. 21. A portion of specimen No. 865 still embedded 

 within the uterus. X 4, reduced \. 



FIG. 22. A portion of specimen No. 435", showing a 

 small villus in mid-portion of the figure, 

 which has an exceptionally long syncytial 

 bud. X 50. 



FIG. 23. A small portion of specimen No. 962, showing 

 a framework of epithelium arising from the 

 chorionic membrane. X 50. 



FIG. 24. Vacuolated masses of syncytium, nodules of 

 trophoblast, and especially garlands com- 

 posed in part of distinct cells of the Lang- 

 hans type. Specimen No. 1324. X 300. 



FIG. 25. An apical trophoblastic nodule from specimen 

 No. 516. X 6. 



FIG. 26. A portion of the chorionic membrane from No. 

 714, showing corrugation of the proliferating 

 epithelium. X 50. 



FIG. 27. A hydatid villus illustrating epithelial con- 

 strictions between successive portions. 

 Specimen No. 714. X 50. 



Fio. 28. Epithelial vesicles within the stroma. Speci- 

 men No. 872. X 180. 



FIG. 29. Extremity of an epithelial vesicle. Specimen 

 No. 872. X 300. 



FIG. 30. Marked syncytial budding and epithelial pro- 

 liferation in specimen No. 874*. X 50. 



FIG. 31. Very slight epithelial proliferation in specimen 

 No. 134. X 50. 



FIG. 32. Extremely marked epithelial proliferation on 

 a small, glassy villus from specimen No. 415. 

 X 95 



FIG. 33. Disappearing capillaries represented by large, 

 incomplete curved outlines. Specimen No. 

 749. X 50 



FIG. 34. Collapsed capillaries in process of degeneration. 

 Specimen No. 712. X 95. 



FIG. 35. The degenerating capillaries show as faint lines 

 only. Specimen No. 651g. X 50. 



FIG. 36. Fenestrated hydatiform villi among others that 

 are quite fibrous. Specimen No. 651d. X 50. 



FIG. 37. A section of villus from No. 510, showing scat- 

 tered Hofbauer cells. X 300. 



FIG. 38. A small portion of a villus from No. 749, showing 

 an accumulation of Hofbauer cells. X 300. 



FIG. 39. A portion of a rather fibrous decidua. Speci- 

 men No. 874". X 300. 



364 



