Origin of Species Variorum

↑ 1 blocks not present in 1859 1860 1861; present in 1866 1869 1872

In how important a manner this has acted, has recently been well shown by Sir J. Lubbock in his remarks on the close similarity of the larvæ of some insects belonging to very different orders, and on the dissimilarity of the larvæ of other insects within the same order, according to their habits of life.

→ From such special 1859 1860 1861

From such 1866 1869

Owing to such 1872

→ the 1859 1860 1861 1872

especially when including a division of labour during the different stages of development, as when a larva during one stage has to search for food, and during another stage has to search for a place of attachment, the 1866

especially when they imply a division of labour during the different stages of development, as when the same larva has during one stage to search for food, and has during another stage to search for a place of attachment, the 1869

→ or active embryos 1859 1860 1861

OMIT 1866 1869 1872

→ and cases could be given of the larvæ of two species, or of two groups of species, differing quite as much, or even more, from each other than do their adult parents. 1859 1860 1861

and cases could be given of the larvæ of two species, or of two groups of species, differing much more from each other, than do their adult parents. 1866

and cases could be given of the larvæ of two species, or of two groups of species, differing more from each other than do the adults. 1869

especially when there is a division of labour during the different stages of development, as when the same larva has during one stage to search for food, and during another stage has to search for a place of attachment. 1872

→ as it certainly is, 1859 1860 1861 1866

OMIT 1869 1872

→ to be the case 1859 1860 1861 1866

to be true 1869

OMIT 1872

of existence. We cannot, for instance, suppose that in the embryos of the vertebrata the peculiar loop-like

courses

course

of the arteries near the branchial slits are related to similar conditions,— in the young mammal which is nourished in the womb of its mother, in the egg of the bird which is hatched in a nest, and in the spawn of a frog under water. We have no more reason to believe in such a relation, than we have to believe that the

similar

same

bones in the hand of a man, wing of a bat, and fin of a porpoise, are related to similar conditions of life. No

good observer

one

~~will~~

will

supposes

suppose

that the stripes on the whelp of a lion, or the spots on the young blackbird, are of

~~any~~

any

use to these

animals.

animals,

~~are~~

are

~~related~~

~~the~~

~~conditions~~

~~which~~

~~they~~

~~are~~

~~exposed.~~

The case, however, is different when an animal during any part of its embryonic career is active, and has to provide for itself. The period of activity may come on earlier or later in life; but whenever it comes on, the adaptation of the larva to its conditions of life is just as perfect and as beautiful as in the adult animal. ↑ →From such special adaptations, →the similarity of the larvæ →or active embryos of allied animals is sometimes

greatly

much

obscured; →and cases could be given of the larvæ of two species, or of two groups of species, differing quite as much, or even more, from each other than do their adult parents. In most cases, however, the

larvæ

larvæ,

though active, still

obey,

obey

more or less

closely,

closely

the law of common embryonic resemblance. Cirripedes afford a good instance of

this;

this:

even the illustrious Cuvier did not perceive that a barnacle