3. That metamorphoses may therefore be divided into two kinds, developmental and adaptional or adaptive.
4. That the apparent abruptness of the changes which insects undergo, arises in great measure from the hardness of their skin, which admits of no gradual alteration of form, and which is itself necessary in order to afford sufficient support to the muscles.
5. The immobility of the pupa or chrysalis depends on the rapidity of the changes going on in it.
6. Although the majority of insects go through three well-marked stages after leaving the egg, still a large number arrive at maturity through a greater or smaller number of slight changes.
7. When the external organs arrive at this final form before the organs of reproduction are matured, these changes are known as metamorphoses; when, on the contrary, the organs of reproduction are functionally perfect before the external organs, or when the creature has the power of budding, then the phenomenon is known as alternation of generations.
CHAPTER V.
ON THE ORIGIN OF INSECTS.
"Personne," says Carl Vogt, “en Europe au moins, n’ose plus soutenir la Création indépendante et de toutes pièces des espèces,” and though this statement is perhaps not strictly correct, still it is no doubt true, that the Doctrine of Evolution, in some form or other, is accepted by most, if not by all, the greatest naturalists of Europe. Yet it is surprising how much, in spite of all that has been written, Mr. Darwin’s views are still misunderstood. Thus Browning, in one of his recent poems, says:—