104 Philippine Journal of Science 1920 
to the fusion of the two optic anlagen, in the course of develop- 
ment, by mechanical injuries. This theory is supported by 
Lewis who produced various grades of cyclops by pricking the 
area located between the optic anlagen. He holds that the col- 
lapse of the wound surfaces affects the approximation of the 
two optic anlagen, and the degree of approximation depends 
on the amount of interocular tissue removed or injured. But 
objections have been raised to the fusion hypothesis; first, on 
the ground that cyclopean eyes are rarely equal, in size and 
extent, to the sum of the two normal eyes combined; second, 
that experiments made by mechanical injuries cannot account 
for results produced by chemical means. 
The most acceptable theory concerning the etiology of mon- 
sters is that of Werber, who concludes from his studies in 1917 
on the origin of monsters that parental metabolic toxemia may 
be held responsible for the production of monstrosities. He 
claims that toxic substances resulting from faulty metabolism 
in the blood of individuals with metabolic disturbances bring 
about such changes as to produce monsters. But in order to 
prove the truth of this theory, individuals suffering from such 
diseases as diabetes, nephritis, etc., should be mated and their 
offspring studied. Such propositions and conditions are eX- 
tremely difficult to attain; however, opportunity was afforded 
the advocate of this theory to imitate the condition by placing 
ova in a certain percentage of acetone, and he obtained all grada- 
tions of monstrosities. The most predominant anomalies he 
obtained were found in the eyes. He contends that the produc- 
tion of a single eye may be due to a blastolytic injury of a re 
stricted area of the anterior end of the early embryonal stage. 
This is assumed to be the area most sensitive to toxic action and 
is the region between the future optic anlagen, or it may eve? 
comprise the anlagen themselves. The size of the part affected 
may be subject to considerable variation: it may include mate- 
rial which would normally correspond to the future interocular 
region and cause an approximation of the potential optic an- 
lagen; it may extend over the primary optic vesicles, eliminat- 
ing parts of them, so that by their coalescence and approxima- 
tion any one of the various degrees of synophthalmic conditions 
may be formed; or it may comprise the whole of one potential 
optic anlage and little or no tissue of the future interocular are 
causing the embryo to develop into a cyclopean monster if the 
sound anlage is shifted medianward, or into an asymmetric 
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