ON THE FATE OF THE HUMAN EMBRYO IN TUBAL PREGNANCY. 25 



We have in our collection one exceptionally good specimen of a tubal pregnancy 

 containing a very small normal embryo. In this specimen, No. 808, the tube is 

 uniformly distended for a distance of about 50 mm., having a diameter of about 

 15 mm. A good reconstruction of this specimen, after it had been cut into numerous 

 sections, showed that the ovum was implanted on the broad ligament side near the 

 uterine end for a distance of about 15 mm. and extended into the tube lumen 

 towards the uterus for a distance of about 10 mm. and towards the abdominal end 

 of the tube for about 40 mm. The tube lumen on the uterine end seems to be per- 

 fectly normal, and at the point of implantation it passes around the ovum on the 

 side opposite the broad ligament. Opposite the middle of the attachment the out- 

 line of the tube is not very sharp, most of the tube wall having disappeared; its 

 outer wall portion is only partially covered with epithelial cells. At this point the 

 space between the ovum and the tube is distinguished by a layer of trophoblast 

 covered by a large plug of necrotic tissue. This extends more or less around the 

 circumference of the ovum until it reaches the point where the pregnancy mass has 

 broken into the tube lumen. From here on the tube is lined with numerous well- 

 formed folds which are more or less separated, probably owing to the distention. 

 Beyond the pregnancy mass, within the inner opening of the tube, the lumen is 

 filled with large, well-formed folds of mucous membrane. Between them there is 

 a small plug of necrotic tissue, belonging to the ovum, but not adherent to the folds. 

 To all appearances we have here a perfectly normal tube wall without any indication 

 of inflammation or any clinical signs of any infectious disease. For some unknown 

 reason the ovum became lodged in the tube, burrowed into the tube lumen in both 

 directions that is, towards the uterus and towards the abdominal wall. Con- 

 siderable change has taken place in the ovum, as it can hardly be considered normal 

 for this stage of development. The ccelom is very small in a transverse direction 

 and has become elongated to correspond somewhat with the shape of the surround- 

 ing clot. The embryo is located in the implanted region, but the ovum is drawn 

 out into the clot on its distal side, being fairly well constricted in its middle; that 

 is, there seems to be a tendency for the chorion to be divided into two parts. The 

 inner part contains the normal embryo, and the outer a small isolated body which 

 seems to be a part of the umbilical vesicle. At any rate, the structure is identical 

 with the umbilical vesicle, but it is not connected. So far as external form is con- 

 cerned the embryo appears to be normal. The organs are sharply defined and the 

 surface is beautifully molded. Sections show that the embryo is normal, except 

 the ventral half of the thoracic spinal cord, which has become dissociated. (See 

 plate 1, fig. 4, and plate 11, figs. 3 and 4.) 



THE TROPHOBLAST. 



The villi of the chorion of No. 808 are unequally divided. On one side, near 

 the tube lumen opposite the implantation, the bare chorionic wall is separated from 

 the lumen by the necrotic plug spoken of above. Opposite this, near the broad 

 ligament, a large tuft of villi reaches into the tube on the uterine side and is well 

 implanted. In the distal end of the clot most of the villi are degenerating; but 



