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From some of these "Zoeopoda" arose all the remaining Malacostracous Crustacea; while, from others, was developed some form analogous to the existing Galeodes, out of which proceeded, by gradual differentiation, all the Myriapoda, Arachnida, and Insecta. I should, be disposed to interpret the facts of the embryological history and of the anatomy of the Arthropoda in a different manner.
Then without expressing his views as to the position and affinities of the Lepismidæ, he remarks "as the upshot of all this, then, while the Collembola are clearly more nearly allied to the Insecta than to the Crustacea or Arachnida, we cannot, I think, regard them as Orthoptera or Neuroptera, or even as true insects.
Cryptogamic vegetation would have the advantage over Phanerogamic; Hydrozoa over Corals; Crustacea over Insecta, and Amphipoda and Isopoda over the higher Crustacea; Cetaceans and Seals over the Primates; the civilization of the Esquimaux over that of the European.
Even towards the nearer provinces of the Myriopoda and Arachnida I can find no bridge. For the Insecta alone, the development of the Malacostraca may perhaps present a point of union.
But nowhere among the Crustacea is there a mode of development comparable to the "complete metamorphosis" of the Insecta, nowhere among the young or adult Crustacea are there forms which might resemble the maggots of the Diptera or Hymenoptera, the larvae of the Coleoptera, or the caterpillars of the Lepidoptera, still less any bearing even a distant resemblance to the quiescent pupae of these animals.
Nevertheless the supposition that the Insecta had for their common ancestor a Zoea which raised itself into a life on land, may be recommended for further examination. Much in what has been adduced above may be erroneous, many an interpretation may have failed, and many a fact may not have been placed in its proper light.
Like many Zoeae, the Insecta possess three pairs of limbs serving for the reception of nourishment, and three pairs serving for locomotion; like the Zoeae they have an abdomen without appendages; as in all Zoeae the mandibles in Insects are destitute of palpi. Certainly but little in common, compared with the much which distinguishes these two animal-forms.
Or, if we represent the divisions of the Articulata like the branching of a tree, we must picture the Collembola as a separate branch, though a small one, and much more closely connected with the Insecta than with the Crustacea or the Arachnida." Lamarck regarded them as more nearly allied to the Crustacea than Insecta.
Hence the difficulties which have embarrassed the naturalists, who adopt the Linnæan classification, in their endeavours to discover determinate characters of distinction between the vermes and the insecta. But no sooner have we passed the borders, than endless variety of form and the bold display of instincts announce, that Nature has succeeded.
The two highest groups of the Annulosa, the Insecta and the Arachnida, are represented in the Coal, either by existing genera, or by forms differing from existing genera in quite minor peculiarities.
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