Origin of Species Variorum

From the remarks just made we can see how by changes of structure in the young, in conformity with changed habits of life, together with inheritance at corresponding ages, animals in certain cases might come to pass through stages of development, perfectly distinct from their primordial, adult condition. ↑ Fritz Müller, who has recently discussed this .. subject with much ability, ... believes that the progenitor of all insects .. resembled an adult insect, and that the caterpillar or maggot stages, as well as the cocoon or pupal stages, have subsequently been acquired; but from this view many naturalists, for instance Sir J. Lubbock, who has likewise recently discussed this subject, would, it is probable, dissent. That certain unusual stages in the metamorphoses of insects have been acquired through adaptation to peculiar habits of life, there can hardly be a doubt: thus the first larval form of a certain beetle, the Sitaris, as described by M. Fabre, is an active, minute insect, furnished with six legs, two long antennæ, and four eyes. These larvæ are hatched in the nests of .. bees; and when the male-bees emerge ... from their burrows in the spring, which they do before the females, the larvæ spring on them, and afterwards crawl on the females whilst paired with the males. As soon as the females lay their eggs ... on the surface of the .. honey stored in their cells, the larvæ of the Sitaris leap on the eggs and devour them. Afterwards these larvæ undergo a complete change; their eyes disappear; their legs and antennæ become rudimentary, and they feed on honey; so that they now more closely resemble the ordinary larvæ of insects; ultimately they undergo a further transformation, and finally emerge as the perfect beetle. Now, if an insect, undergoing transformations like those of the Sitaris, were to become the progenitor of a whole new class of insects, their course of develop- ment