No. 1.] ORIGIN OF HUMAN MONSTERS. 43 
MonstTERs IN Wuicu Tissues Must Have BEEN DESTROYED 
—MacGnesium MONSTERS, CYCLOPIA AND CLuB-FOoT. 
It has been repeately noted by experimental teratologists 
that, whenever the malformation of an embryo is slight, there is 
a general retardation of development of the whole body which 
is more marked in some portions of the embryo than in others. 
Thus it is stated that the tail of an embryo is atrophic, or 
even club-shaped, a condition which cannot be brought about 
without some destruction or rearrangement of its tissues. 
In the human embryo there are all gradations of form 
between typical anencephaly, atrophic head and deformed 
head; in fact, pure types are rarely seen. These varieties can 
be brought together under the general heading of atrophic 
heads. The tissue change in them ranges from histolysis to 
dissociation or even to maceration. In a general way the 
following table gives the frequency of variations of path- 
ological embryos and of monsters per 100,000 pregnancies. 
The figures from which the table has been constructed will be 
found on pages 26, 27, 65 and 66, and may be considered to 
be fairly reliable: 
Peepasvcics! Births. Normal Embryos Pathological Monsters. 
and Foetuses. Embryos. 
100,000 81,000 12,000 7,000 615 
Bly CrOCepnaltiSe orcs Weise. at ses reuse “pr EO) 
BPO cidde de eae a. rcle cc Mit arn chee ss 953 Aas 
JENS OR S200 ae ie oe ae oe ng 574 119 
“3 [Cand 10 ae a ee 410 47 
ACEsCGIOEIMIEM: sc, 4. 6ilS.2 5,0 omen wie 697 96 
Wetormed Cvesnne an tac ea sce 123 25 
Metonmneds extrenuties! 22 °....0./.5 2. «'s 697 ELS 
The figures given under monsters are actual figures, those 
for hydrocephalus, etc., being from Panum, in which the 
total number is 618. This is practically equal to the 615 which 
I have obtained from various authors. My data, which are 
from 163 pathological ova, were multiplied by 41 to bring 
