SUMMARY. 105 



growing conceptus must overcome, for the latter is periodically, or at least inter- 

 mittently, subjected to the force exerted by tubal peristalsis whenever the tube 

 attempts to rid itself of its unusual guest. 



It is interesting that there does not seem to be the least evidence that the 

 tubal musculature regularly undergoes a marked hypertrophy in these cases. 

 Although I have examined carefully a series of specimens with regard to this 

 point, I have never been able to find any indication of a protective reaction on the 

 part of the tubal musculature or of the other tissues which were being invaded and 

 destroyed by the proliferating trophoblast. Aside from a certain amount of hyper- 

 emia and of infiltration, which may be provoked by the presence of the conceptus 

 within the tube, the latter seems to be largely passive, except for the intermittent 

 attempts at tubal abortion. These may be provoked very largely by the destruc- 

 tive and irritative effects of the trophoblast, and only to a minor degree through 

 mechanical distention incident to the increase in size of the conceptus, for this 

 distention necessarily is an extremely gradual one. This, however, does not affect 

 the fact that if more or less sudden hemorrhage rapidly distends the tube, the latter 

 probably may be thrown into violent peristalsis through this agency alone and also 

 undergo marked hypertrophy, under conditions of gradual distention by clot alone. 



The tissue changes observed in the tubes were far less varied than those 

 seen in the uterus. This was due partly to the absence of anything comparable to 

 the decidua, and also to the absence of specimens that had been retained an 

 unusually long time. Densely fibrous villi were not common; hyalin degeneration 

 was rare, and calcification, except perhaps in its incipient stages, was not observed. 

 Since the villi were scattered about in the blood-clot, coagulation necroses, or mat- 

 ting, were practically absent. Marked maceration changes were exceedingly 

 common, however, and most evident where the surrounding blood was least 

 well preserved. Almost all save a few specimens were contained in much clot, 

 but since nothing comparable to a detachable decidua intervened between the 

 implanted villi and the tube-wall, such villi frequently had been left in loco, even 

 when they had undergone marked degeneration. In several specimens the degen- 

 erate muscle-cells, together with the degenerate trophoblast overlying them, from 

 which they could not be distinguished, formed a considerable layer between the 

 tips of the villi and the tube-wall. In others this layer appeared roughly like a 

 decidua, although a layer of fibrinoid was never seen. 



Aside from the many instances of splendid hydatiform degenerations, no other 

 change than a fibrosis of the stroma of the villi was encountered. This fibrosis 

 seemed to be more common in cases of severe infection, especially if evident also 

 in the contained clot. Hofbauer cells, when present at all, were few, and instances 

 of villi which were filled with them were not found. Aside from maceration, the 

 changes in the stroma and in the vessels of the villi were limited to hydatiform 

 degeneration and fibrosis. The syncytium and trophoblast often gave evidence 

 of having been very active, however, a fact which may be due largely to the 

 recurring accessions of fresh blood which bathed the chorionic vesicle, and which 

 not only nourished but probably also stimulated both villi and syncytium to 



