ON THE FATE OF THE HUMAN EMBRYO IN TUBAL PREGNANCY. 39 



most part the walls of the chorion have degenerated, showing all stages of necrosis. 

 It appears as though the nutrition of the ovum had been cut off. At no point is it 

 directly attached to the wall of the tube, though the villi are intermingled with its 

 folds, as shown in plate 9, figure 3. The villi are also undergoing fibrous degeneration 

 and the ccelom is filled with a mottled magma, into which there radiate strands of 

 mesenchyme cells from the chorionic membrane, as shown in plate 3, figure 2. 



It is necessary at this point to discuss briefly the nature of the magma as well 

 as the various kinds of degeneration that the villi may undergo. The nature of the 

 magma has been a puzzle to embryologists ever since it was first described by 

 Valpeau. In the course of time it was shown that magma is present in all normal 

 ova, and according to Retzius it first fills the entire exocoelom. As the amnion 

 distends the magma is swept along ahead of it and ultimately comes to lie as a 

 delicate layer between the amnion and the chorion. This observation has been 

 confirmed many times in the study of the normal human ova and the magma has 

 been described by Keibel in the ova of ape embryos. Giacomini first pointed out 

 that an increase of magma indicates that the ovum is pathological and that it does 

 not contain a normal embryo. In fact, whenever we have an embryo which is 

 obscured by an excessive amount of magma, we are sure that no normal embryo 

 will be found. In my various papers on pathological embryos I have emphasized 

 this point and have also called attention to two kinds of magma, a fresh reticular 

 and an older granular variety. It appears that as the magma increases in quantity 

 a granular mass is deposited between the fibrillae. 



I have also called attention to the fact that the amnion, especially when it is 

 greatly distended, often contains a granular mass, but in general this substance is 

 gelatinous when the specimen has been fixed in formalin. I was formerly inclined 

 to believe that when this became inspissated we then had granular magma in its 

 purest state and that reticular magma belonged to the ccelom and granular magma 

 to the amniotic cavity. Further investigation, however, seems to demonstrate that 

 both kinds of magma belong to the ccelom, and the substance so frequently found 

 within the amnion is not to be confused with them. At any rate, it seems better at 

 present to speak of this as a third kind of magma, possibly as amniotic magma or 

 gelatinous magma. Until we have further information upon this point it may be 

 better to ignore the amniotic magma. A careful study of very young ova, like those 

 of Bryce and Teacher and of Peters, shows that the entire ccelom is at first filled 

 with dense reticular fibrils, with which are intermingled some mesoderm cells. This 

 is especially well brought out by Grosser in his study of Peters's specimen. He is 

 inclined to believe that two small spaces form within the magma on either side of the 

 embryo. These spaces form the primitive exocoelom. The magma fibrils encircle 

 these and radiate to blend with the chorionic wall. An interpretation of this 

 specimen is shown in Grosser's figure 97 in the Handbook of Embryology. It is 

 quite proper to conclude from this figure, as well as from Peters's own figure, that 

 the magma is only a portion of the chorionic wall detached to fill the ccelom of the 

 older embryologists in fact, this is Grosser's view. Stating it somewhat differently, 

 we might say that as the ovum is expanding to pass from the Bryce and Teacher 



