ON THE FATE OF THE HUMAN EMBRYO IN TUBAL, PREGNANCY. 31 



An even more perfect specimen of implantation is possibly that of No. 670. 

 The embryo in this case was 12.5 mm. long and the spaces between the chorionic 

 wall and the tube wall are largely empty. There are, however, several hemorrhagic 

 areas about 5 mm. in diameter. Where the villi come in contact with these there 

 is a marked layer of fibrinoid necrosis, a sample of which is shown in plate 2, figure 3. 

 It appears as though this substance may arise from all kinds of tissue, either mater- 

 nal or embryonal. In the figure just referred to it seems to rise from degenerate 

 trophoblastic cells. In this case we seem to have the reverse of the process shown 

 in No. 109. There the trophoblast is destroying the blood clot. Here the blood 

 clot is surrounding the zone of necrotic tissue which is composed partly of tropho- 

 blast. Elsewhere in this specimen are large strands of this fibrinoid substance, 

 which often reach into the tube wall. In general, however, the trophoblast is 

 extremely active and markedly vacuolated. Where the trophoblast is heaped up 

 into large islands, their centers are often necrotic, forming yellow nodules, which 

 in turn are being invaded by vacuolated syncytium. This condition is often seen 

 in uterine implantation and has been described and pictured by Grosser. Undoubt- 

 edly we are here dealing with the normal destruction of less-favored villi. Adjacent 

 to one of these masses are several villi, which are being invaded by their own tropho- 

 blast. This condition is very pronounced in this specimen and is well illustrated 

 in plate 2, figure 7. In this same figure numerous Hofbauer cells are seen It would 

 seem possible that these Hofbauer cells are free trophoblast cells within the meso- 

 derm of the villus, an opinion already expressed by me in my paper on monsters. 

 As in No. 109, we have here a beautiful case of successful implantation in the tube. 

 There are but few hemorrhages in the intervillous spaces, the trophoblast is exten- 

 sive, and the villi appear to be normal. In this case we also have a normal embryo. 

 In contrast with these two specimens, No. 535 contains a normal embryo 11 mm. long, 

 and shows an extensive intervillous hemorrhage. There are some slight changes 

 in this embryo; the branchial arches are partly obliterated, and the body wall is 

 sufficiently transparent to allow the ribs to be seen, so that in all probability the 

 embryo was dead before the tube was removed. In this case the tubal mass is very 

 large, about 55 mm. in diameter, and the tube wall is thick, dense, and hemorrhagic, 

 measuring about 15 mm. Within this hemorrhagic mass all stages of degeneration 

 of villi can be noted; plaques of white necrosis alternate with fresh hemorrhages. 

 Scattered through the mass are strands of leucocytes encircling the ovum that 

 is, at its juncture with the tube wall, a marked infiltration with leucocytes can 

 be noted. The inflammatory process is quite extensive and the necrosis of the villi 

 and its trophoblast is quite complete. We have here an example of the effect of 

 intervillous hemorrhage upon the ovum. It appears to cause its destruction. 



The next older stage, which seems to be of value as regards the nature of implan- 

 tation, is seen in an embryo 17 mm. long (No. 676). This appears to be normal 

 and the ovum had been peeled out of the tube before it came to us, so that it was 

 impossible to make a careful examination of the tube wall in its relation to the villi 

 of the chorion. We determined that the embryonic cavity was lined with a clot 

 and sections of this clot show that it was perforated with normal villi which were 



