Origin of Species Variorum

→ OMIT 1869 1872

and likewise a close similarity in the embryos of widely different animals within the same class, 1859 1860

and like-wise a close similarity in the embryos of widely different animals within the same class, 1861

and like-wise a close similarity in the embryos of different animals within the same class, 1866

→ are tempted 1869 1872

might be led 1859 1860 1861 1866

→ this difference as in some manner 1869

these facts as necessarily contingent in some manner 1859 1860 1861

these facts as in some manner necessarily contingent 1866

this difference as in some necessary manner contingent 1872

→ necessarily contingent on 1869

on 1859 1860 1861 1866 1872

↑ 2 blocks not present in 1859 1860 1861 1866 1869; present in 1872

In some whole groups of animals and in certain members of other groups this is the case, and the embryo does not at any period differ widely from the adult: thus Owen has remarked in regard to cuttlefish, "there is no metamorphosis; the cephalopodic character is manifested long before the parts of the embryo are completed." Land-shells and fresh-water crustaceans are born having their proper forms, whilst the marine members of the same two great classes pass through considerable and often great changes during their development.

→ this is the case, and the 1869

the 1859 1860 1861 1866

→ changes during their development. 1869

changes. 1866

→ The larvæ of most insects pass through a worm-like stage, whether they are active and 1869 1872

The larvæ of insects, whether 1859 1860 1861

With almost all insects, the larvæ, whether 1866

→ diversified 1869 1872

the most diverse and active 1859 1860 1861

diversified and active 1866

→ from being placed in the midst of proper nutriment 1869 1872

being fed by their parents or placed in the midst of proper nutriment, 1859 1860 1861

being placed in the midst of proper nutriment or fed by their parents, 1866

→ or from being fed by their parents; 1869 1872

yet nearly all pass through a similar worm-like stage of development; 1859 1860 1861 1866

→ of the development of this insect, by Professor Huxley, 1869 1872

by Professor Huxley of the development of this insect, 1859 1860 1861 1866

~~and very~~

and very

simple eye-spot. In this last and complete state, cirripedes may be considered as either more highly or more lowly organised than they were in the larval condition. But in some genera the larvæ become developed

~~either~~

either

into hermaphrodites having the ordinary structure,

and

into what I have called complemental

males:

males;

males,

and in the

latter

latter,

the development has assuredly been

retrograde,

retrograde;

for the male is a mere sack, which lives for a short

time

time,

and is destitute of mouth, stomach,

and every

other

organ

organs

of importance, excepting

for

those for

reproduction.

We are so much accustomed to see

differences

a difference

in structure between the embryo and the adult, →OMIT that we →are tempted to look at →this difference as in some manner →necessarily contingent on growth. But there is no

obvious

....

reason why, for instance, the

wing

wings

of a bat, or the

fin

fins

of a porpoise, should not have been sketched out with all

the

their

parts in proper proportion, as soon as any

part

structure

became

visible

the

embryo.

↑

And in

some whole groups of animals and in certain members of other

groups,

groups

→this is the case, and the embryo does not at any period differ widely from the adult: thus Owen has remarked in regard to cuttle-fish, "there is no metamorphosis; the cephalopodic character is manifested long before the parts of the embryo are

completed;"

and

again

spiders,

"there

nothing

worthy

called

metamorphosis."

Land-shells and fresh-water crustaceans are born

with

having

their proper

forms,

form,

whilst the marine members of

these

the same

two great classes pass through considerable and often great

developmental

....

→changes during their development. Spiders, again, barely undergo any metamorphosis. →The larvæ of most insects pass through a worm-like stage, whether they are active and adapted to →diversified habits, or

quite

remaining

are

inactive,

inactive

→from being placed in the midst of proper nutriment →or from being fed by their parents; but in some few cases, as in that of Aphis, if we look to the admirable drawings →of the development of this insect, by Professor Huxley,