1925 ] A Specimen of Melanoplus differentialis Thomas 
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A SPECIMEN OF MELANOPLUS DIFFERENTIALIS 
THOMAS WITH FOUR OCELLI* 
Robert D. Glasgow 
University of Illinois. 
For some reason contributions to the literature of teratology 
from insect examples have been made in far greater numbers by 
European entomologists than by their American colleagues, yet 
there seems to be no apparent reason why abnormalities should 
be proportionately rarer among American insects or in the 
materials handled by American students of entomology. The 
writer has himself encountered no less than six interesting ex- 
amples of arthropodan malformations in the course of his work, 
and every entomologist who has examined carefully any con- 
siderable amount of insect material must have observed some 
specimens which presented noteworthy abnormalities that should 
be recorded in the literature of biology, and thus made available 
for consideration by investigators who may have a special interest 
in these phenomena. 
From the nature of these phenomena the occurrence of 
examples must be sporadic, and since each case standing alone 
may seem to the observer to have little signficance, they are 
likely to be unheeded, or at least unrecorded, and consequently 
lost to science. It is probable also that many examples of insect 
abnomalities have never been reported because the observers 
have hesitated simply to describe them without comment, and 
have not felt prepared to supplement their presentation with a 
plausible explanation or interpretation. 
Not only is an interpretation not necessary in reporting 
examples of such malformations of insects, or of other organisms, 
but indeed any attempt to formulate an interpretation of such 
phenomena is scarcely warranted, unless the observer has studied 
a considerable body of data accumulated from many similar or 
related cases. It is sufficient simply to place each example on 
Contribution from the Entomological Laboratories of the University of 
Illinois, Number 92. 
(Read at the Cincinnati meeting of the Entomological Society of America, 
December 27, 1924.) 
