Infections of the Gravid Uterus 463 



brown color and frequently desiccated. It varies in extent 

 from one-fourth inch or less to eight or ten inches. The 

 necrosed part lies free within the horn, surrounded by a 

 dirty yellowish or yellowish brown flocculent exudate, some- 

 times watery, sometimes of pap-like consistency. Some- 

 times the necrotic tip is flat, crumpled and desiccated ; some- 

 times it is soft and pliable, and its lumen persists in continu- 

 ity with the allantoic sac. Rarely the amniotic tips partici- 

 pate in the necrosis and become adherent in the necrotic 

 allantoic area. The extremities of the amnion thus become 

 fixed in the apices of the allantois, the amnion is incapable 

 of contracting about the embryo, the tension upon the am- 

 nion at its attachment to the ventral floor of the embryo be- 

 comes too great, the embryo everts, and schistocormus re- 

 flexus follows. 



Associated with such necrosis of the membranes, there 

 exists as a rule a macroscopically recognizable endometritis 

 of the contiguous uterine mucosa. The mucosa, definitely 

 thickened and edematous, generally bears upon the surface 

 dirty yellowish or reddish sediment, resembling brick-dust 

 and closely adherent. There are wide variations. In nu- 

 merous cases the exudate is of a dirty yellowish-brown 

 color, tenacious and abundant. In some cases, as shown in 

 Colored Plate III, the exudate fills the non-gravid horn from 

 apex to base and presents the characters of "the exudate of 

 contagious abortion." Between the extremes named every 

 grade of endometritis is seen. The volume and type of en- 

 dometritis correspond with the necrosis of the tip of the 

 fetal sac. The necrosis of the tip and the endometritis are 

 regularly greatest in the non-gravid horn. It is possible 

 that in some cases the pre-conceptional infection is so great 

 in one horn that fertilization on that side is blocked and 

 pregnancy occurs on the side of least infection. In such 

 case the lesions would naturally be most marked upon the 

 non-gravid side. I think, however, that this hypothesis ex- 

 plains few cases. The more probable cause of the variation 

 is the lesser vitality of the membranes in the non-gravid 

 horn. They are far less vascular and, in harmony with 



