ere highly developed insects, such
as May flies, grasshoppers, etc., in the Devonian rocks of New
Brunswick, leading us to expect the discovery of low insects even in the
Upper Silurian rocks. At any rate this discovery pushes back the origin
of insects beyond a time when there were true Zoeae, as the shrimps and
their allies are not actually known to exist so far back as the
Silurian, not having as yet been found below the coal measures.
The view that the insects were derived from a Zoea was also sustained by
Friedrich Brauer, the distinguished entomologist of Vienna, in a
paper[18] read in March, 1869. Following the suggestion of Fritz Mueller
and Haeckel, he derives the ancestry of insects from the Zoea of crabs
and shrimps. However, he regards the Podurids as the more immediate
ancestors of the true insects, selecting Campodea as the type of such an
ancestral form, remarking that the "Campodea-stage has for the Insects
and Myriopods the same value as the Zoea for the Crustacea." He says
nothing regarding the spiders and mites.
At the same time[19] the writer, in criticising Haeckel's views of the
derivation of insects from the Crustacea (ignorant of the fact that he
had also suggested that the insects were possibly derived directly from
the worms, and also independently of Brauer's opinions) declared his
belief that though it seemed premature, after the discovery of highly
organized winged insects in rocks so ancient as the Devonian, and with
the late discovery of a land plant in the Lower Silurian rocks of
Sweden,[20] to even guess as to the ancestry of insects, yet he would
suggest that, instead of being derived from some Zoea, "the ancestors of
the insects (including the six-footed insects, spiders and myriopods)
must have been worm-like and aquatic, and when the type became
terrestrial we would imagine a form somewhat like the young Pauropus,
which combines in a remarkable degree the characters of the myriopods
and the degraded wingless insects, such as the Smynthurus, Podura, etc.
Some such forms may have been introduced late in the Silurian period,
for the interesting discoveries of fossil insects in the Devonian of New
Brunswick, by Messrs. Hartt and Scudder, and those discovered by Messrs.
Meek and Worthen in the lower part of the Coal Measures at Morris,
Illinois, and described by Mr. Scudder, reveal carboniferous myriopods
(two species of Euphorberia) more highly organized than Pauropus, and a
carboni
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