No. 1.] ORIGIN OF HUMAN MONSTERS. 131 
the mesoderm, which is well infiltrated with round cells. The 
“inflammatory” process extends along the middle of the back 
to the top of the head. Immediately over the cord, in the 
middle of the back, the infiltration of cells extends throughout 
the mesoderm and includes the meninges of the cord, showing 
a similarity with the changes in the case of spina bifida in 
the embryo described recently by Fischel (Plate 1). It cer- 
tainly would be very easy for a localized affair like this to pre- 
pare the way for the production of spina bifida. Possibly in 
the course of time, after my pathological collection contains 
thousands of specimens, intermediate stages will be found 
which will show that the changes found in this embryo favor 
the production of monsters with spina bifida. 
Another embryo in which the spinal canal is broken open 
behind (No. 226) shows extensive alterations in its tissues. 
The changes in the chorion indicate that the circulation within 
the embryo had ceased some time before the abortion. Its 
mesoderm is fibrous and almost devoid of blood-vessels. 
Between the amnion and chorion there is a iayer of organized 
blood from the mother, showing that there must have been a 
rupture some time before the abortion. 
The external form of the embryo is interesting, the trunk, 
extremities and cord being normal in form, while there is a 
marked defect in the head. Here on the dorsal side the de- 
structive process has also included the upper part of the 
spinal cord, producing complete spina bifida. The rest of the 
central nervous system is still intact, but the cerebral vesicles 
are reduced in size and are exposed to the exterior of the 
body. The free end of the upper part of the cord is broken 
quite abruptly, while that of the lower part of the medulla is 
rounded off, 7. ¢., it appears to have healed over. The larger 
portion of the cervical cord is missing; it may have escaped 
through the dorsal opening. 
There are marked changes in the tissues of the body, which 
may be due to maceration rather than dissociation. The con- 
nective tissues, including the bone and the vascular system, 
are well preserved, with more or less round-celled infiltration 
and possibly some fibrous thickening. 
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