POST-MORTEM INTRAUTERINE CHANGES. 295 



as exemplified in Nos. 1462 and 1309 (figures 224 and 225), which are purely acci- 

 dental forms. As maceration becomes extreme, even without the presence of 

 putrefaction, marked softening and distortion take place and the face may be 

 drawn into grimaces, as illustrated by No. 1775 (fig. 226) and by other specimens 

 previously represented. In these older specimens the epidermis, instead of falling 

 off in flakes or hanging in streamers, especially from the extremities of the digits, 

 may become rolled up and accumulate in welts, especially at points of contact of 

 the extremities, as illustrated in No. 1859 (fig. 64, plate 5, Chap. IV). 



If dehydration occurs under sterile conditions, the transition from such a 

 specimen as No. 1859 to 1474a, shown in figure 61 (plate 5, Chap. IV.), is an easy 

 one, and if continued beyond this stage it may eventually lead to typical mummi- 

 fication. If the amniotic fluid is finally completely or almost completely absorbed 

 and the uterus then contracts upon the specimen, such rolled-up forms as Nos. 

 1525, 1976 (figures 227 and 228) and No. 1041 (figure 40, plate 4, Chap. IV.) may 

 result. Sometimes the placenta and membranes of these long-retained, leathery 

 specimens are found in the form of a firm covering with a small opening through 

 which the fetus has escaped, as illustrated by No. 1850, a fetus of 17 mm., shown 

 in figure 229. 



In other instances the fetal tissues, instead of becoming dehydrated, as in 

 case of the above and No. 1295a, shown in figure 230, remain soft, as represented 

 in a comparatively early stage by No. 1350, 66 mm. long, shown in figure 61 (plate 

 5, Chap. IV). 



A more advanced stage of this process is represented by Nos. 2034 and 1925, 

 fetuses 96.5 and 147 mm. long respectively, shown in figure 234 and figure 48 (plate 

 5, Chap. IX). If this process of maceration becomes extreme, or if putrefac- 

 tion supervenes, such disintegrated forms as No. 1515 (fig. 50, plate 5, Chap. IV) 

 are finally produced, and the stage of disarticulation is at last reached. 



That the advent of rigor mortis does not necessarily change the attitude of 

 young embryos is suggested from occurrences observed personally under experi- 

 mental conditions. As long as the amnion closely invests a mammalian embryo, 

 the extremities of the latter can not become extended during rigor, and hence may 

 retain the intrauterine position. The same thing holds, to a considerable extent 

 at least, for the trunk also, for neither is it so free to extend as when the amnion 

 has been opened or been removed. In the human conceptus the amnion soon 

 becomes sufficiently large, however, but coagulum could have a similar influence. 



Although little is known regarding intrauterine rigor mortis, Wolff (1903) 

 stated that it is not rare, and held that an accumulation of waste products pro- 

 duced in consequence of circulating disturbances in the mother may be responsible 

 for its early advent. In any case it probably is quite transitory, and the later 

 rigidity of aborted cyemata undoubtedly must be due to something else. 



At present we are not in position to accurately evaluate slight changes in 

 bodily form of cyemata, for as long as the exact form of normal cyemata remains 

 undetermined, it is inevitable that macerated specimens will be mistaken for and 

 represented as normal in form, even in contemporary embryologies. Abnormal 



