ON THE FATE OF THE HUMAN EMBRYO IN TUBAL PREGNANCY. 9 



I wish to express my thanks especially to Dr. Herbert M. Evans, Research 

 Associate in the Carnegie Institution of Washington, for his successful efforts in 

 collecting specimens and for his aid in working up embryological material. 



During the past two years it has been possible to expedite the work through 

 generous aid from the Carnegie Institution of Washington. Much better histories 

 are now obtained than formerly, thanks to the efficiency of a private secretary; 

 microscopic examinations have been greatly facilitated by competent technical 

 assistants, and the illustrations have been markedly improved through the skill 

 of a talented artist. A study of the protocols will show that those of recent date 

 are more complete than the earlier ones. 



The specimens here described, together with the rest of my human embryos, 

 have been presented to the Carnegie Institution of Washington to form the nucleus 

 of the collection of its newly established Department of Embryology. 



CAUSE OF TUBAL PREGNANCY. 



According to Williams, it is now generally admitted that tubal pregnancy is 

 due to a preceding salpingitis, which interferes in some way with the downward 

 movement of the fertilized ovum. This idea had previously been put forward by 

 Schroeder and Tait, but as it was not definitely known at that time that fertiliza- 

 tion takes place in the tube, the theory did not seem to explain fully the occurrence 

 of tubal pregnancy and therefore did not meet with immediate acceptance. More 

 careful anatomical studies by Williams and other investigators demonstrated that 

 under certain conditions and in certain cases tubal pregnancy was due to normal 

 diverticula from the tube lumen, which caught up the fertilized ovum in its passage 

 towards the uterus. Nevertheless, subsequent studies have demonstrated that 

 this would account for a very small number of cases, leaving the cause in the larger 

 number to be explained in some other way. 



The view held at the present day is supported by proof that in many cases a 

 tubal pregnancy has been preceded by pelvic inflammatory trouble. Thus Diihrs- 

 sen, Mandl and Schmidt, Klistner, Petersen, Runge, and others were able to elicit 

 a history of gonorrheal salpingitis or of inflammatory lesions of the appendages in 

 more than two-thirds of their cases. But, again, after it had been demonstrated 

 that the arrest of the ovum was not always due to the destruction of the cilia by 

 the inflammatory process, great difficulty was experienced in explaining the connec- 

 tion between the two conditions. In 1912, however, Opitz found definite histo- 

 logical inflammatory lesions in two-thirds of his specimens, and, even when they 

 were absent, noted that the tips of many of the folds of the mucosa had become fused 

 together, so that the section showed in places the cribriform appearance character- 

 istic of the so-called follicular salpingitis, and as similar lesions were frequently 

 present in the opposite non-pregnant tube, he held that they afforded a very satis- 

 factory explanation for the arrest of the ovum. He assumed that some of the canals 

 inclosed between the adherent folds communicated freely with the main lumen of 

 the tube, but ended blindly at the other extremity, so that if a fertilized ovum were 

 arrested in a cul-de-sac a tubal pregnancy would develop. 



