No. 1.] ORIGIN OF HUMAN MONSTERS. 53 
is, the tissues of an embryo as normally formed have become 
swollen, are disintegrating and strange cells are wandering 
through them. In His’s opinion such changes cannot be 
viewed as primary, but rather as secondary conditions. 
The other student of pathological embryology, Giacomini,’ 
emphasizes the necessity of studying the form and structure 
of the decidua in normal as well as in pathological ova, for 
at this point mechanical and nutritive influences must occur, 
which are of prime importance in the production of early path- 
ological embryos. He predicted that such a study, together 
with experiments upon lower animals, would ultimately ex- 
plain the origin of monsters. 
There is one more opinion, from the hundreds upon this 
subject, which I must not omit. It is from O. Hertwig,’ in 
his more or less general article on the production of spina 
bifida in Axolotl. After stating that a .6 per cent solution 
of NaCl will produce spina bifida in frogs and a .7 per cent 
solution will produce the same kind of monster in Axolotl, he 
asks whether it is not possible that some similar method is 
employed by nature to produce spina bifida in man? Is it 
not possible for chemical substances in the blood—as alcohol, 
toxines or medicines—to pass from the uterus to the ovum 
and make it monstrous? Evidently he believes that the power 
to become monstrous is not inherited, but is due to external 
influences. 
It is extremely difficult, if not impossible, to prove directly 
that the primary changes which produce pathological ova are 
in the chorion and not in the embryo. I find in glancing over 
the tables which follow, with the discussion of the individual 
specimens, that among 143 pathological specimens but fifteen 
appear to have a normal chorion, and that in thirty-five the 
chorion is sufficiently infiltrated with leucocytes to indicate 
that some inflamamtory process was present in the uterus. In 
all of the specimens excepting the fifteen in which the chorion 
"Giacomini, Merkel u. Bonnet, Ergebnisse, IV, 1804. 
*O. Hertwig, Gegenbaur’s Festschrift, II, 1896. 
