FETUS COMPRESSUS. 93 



pressure, although such usage is at variance with the historical meaning and the 

 usual application of the term. Moreover, very macerated fetuses, the forms of 

 which have not been very materially changed, are not included. These things 

 must be borne in mind in order to avoid misunderstanding. It is true that some 

 of the so-called fetus compressi look as though they had been subjected to pres- 

 sure, and in some instances, even of single pregnancy, there is no doubt whatever 

 about this. Other fetuses look compressed, although a quantity of liquor 

 amnii seemingly sufficient to prevent direct uterine pressure still surrounds 

 them. The head is collapsed from side to side, the hands and feet are flattened, 

 and the trunk also is collapsed. In most of these cases the appearance of com- 

 pression is apparent only, and probably resulted from the softening and collapse 

 of the tissues consequent upon maceration and dehydration under aseptic condi- 

 tions. The skull sometimes is practically devoid of brain tissue and decidedly 

 flattened, all the tissues have become degenerate and necrotic, and those of adjoin- 

 ing parts have often fused more or less, so as to obliterate the natural boundaries. 



If, as stated, mummification sometimes may occur while the fetus is contained 

 in a large amount of fluid, it would seem to have to result from chemical changes 

 in the amniotic fluid. Indeed, it not only is conceivable but inevitable that the 

 composition of the amniotic fluid is changed soon after the death of the fetus. 

 As is well known, death of the membranes makes them more permeable, and 

 hence offers greater facility for the absorption of fluid, thus leading to the greater 

 concentration of the liquor amnii, with consequent dehydration of the fetus. It 

 is evident, however, that absorption must be slow, for otherwise the amniotic 

 fluid, although rarely large in quantity, would soon be absorbed and the fetus would 

 subsequently be subjected to direct pressure from the uterine wall. Sometimes, 

 indeed, such is the case, and then the macerated or mummified fetus may be rolled 

 up firmly into a ball, as illustrated by Nos. 921 and 1041, shown in figures 39 

 and 40. In the last case the decidua, placenta, and membranes were wrapped 

 tightly around the fetus, the whole constituting a firm, rounded mass. 



It is difficult to characterize this group as a whole, because it contains such 

 diverse things as portions of a cord, material from curettage, embryonic fragments 

 of mutilated normal specimens, as well as macerated fetuses falling among the 

 groups of the nodular, cylindrical, stunted, or normal. Figures 41 to 50 inclusive 

 afford some idea of the diversity existing among the specimens of this group. 

 This diversity is extreme, not only in form, size, and age, but also in the matter 

 of preservation. No. 1245 (fig. 41) is a good illustration of fragments. Whether 

 they came from specimens which developed under normal or pathologic conditions 

 it was not always possible to state, even upon microscopic examination, for the 

 decidua was not always included. No. 1806 (fig. 43), though classed in this 

 group, was originally described as normal in form and could be placed among 

 grade 3 of the normal division, for some specimens in this grade show even 

 greater maceration. 



Specimen No. 651a (fig. 58) and to a lesser degree No. 1301 (fig. 44) illustrate 

 beginning changes in form which, though slight, are quite characteristic of many 

 of the specimens of this group, and when present always exclude them from the 



