ON THE FATE OP THE HUMAN EMBRYO IN TUBAL PREGNANCY. 27 



blending with the processes of adjacent syncytium, thus forming a curious network 

 as shown in plate 1, figure 3. This type of trophoblast seems to be most pro- 

 nounced where there is great activity, i. e., when the tube is being eroded. It 

 appears to throw up a dam to prevent excessive hemorrhage or to engulf the blood 

 escaping from the freshly tapped blood vessels. In fact, the vacuoles are filled 

 partly with healthy, partly with disintegrating blood corpuscles, and partly with a 

 clear fluid. The dam thus thrown up makes a sieve through which the blood per- 

 colates on its way to destruction. Is it not probable that in this way pabulum 

 is formed for the ovum? (See plate 1, fig. 4.) 



The vacuolated syncytium seems to be identical with the variety of tropho- 

 blast called plasmodium by Bryce and Teacher. This is well shown in their Plate V. 

 It can also be recognized in the illustration by Peters; for example, in his figure 14, 

 Plate VI, and again by Jung, figure 19, Plate VII. 



In the lakelets between the large strands of syncytium the red blood corpuscles 

 are well formed and sharply defined, but as the blood comes in closer contact with 

 the trophoblast we see all stages of disintegration. They break up into small 

 granules, the finer of which do not stain so intensely as blood and often run together 

 in large masses, which sometimes in the neighborhood of syncytium are easily con- 

 fused with it. Many of the granules in properly stained specimens are intensely 

 red, much more so than normal corpuscles. These may be seen within the proto- 

 plasm of the syncytium and sometimes within the vacuoles, and often within ordinary 

 trophoblast cells. The minute granules, which stain intensely red, vary in size, but 

 are usually about as large as the chromatin of the nuclei, though they often fade off 

 into the ultramicroscopic. Especially is this so in the neighborhood of the masses 

 which are easily confused with the syncytium. It appears, then, that the corpuscles 

 first break down into intensely staining granules, which are partly taken up by the cells 

 and partly undergo further transformation in a homogeneous mass. The descrip- 

 tion here given rests upon specimens which have been counterstained in eosin, 

 aurantia, and orange G, one of which is shown (plate 1, fig. 4). 



The chorionic wall in No. 808 is for most part quite thin and at points it seems 

 to be ruptured. In the region of the embryo the mesoderm of the villi is quite 

 normal, being composed of delicate fibrillse arising from the tips of the multipolar 

 cells. Scattered throughout this tissue are numerous large cells with a delicate 

 protoplasm, which usually takes on some of the counterstain. These are the 

 Hofbauer cells, so frequently seen in pathological villi. Some distance from the 

 embryo the villi are mostly fibrous and are undergoing all sorts of degenerative 

 processes; that is, they are dying. 



The coelom is long drawn out and fully constricted at one point to correspond 

 with the shape of the chorion. In the neighborhood of the embryo it is entirely 

 filled with the amnion, but in the small spaces between the amnion and the chorion 

 is a granular deposit containing numerous maternal red blood corpuscles. As 

 these are embedded within this granular mass, they must have lodged there while 

 the specimen was still living. There are also numerous nucleated cells in this region 

 which appear to have wandered from the embryo. 



