Origin of Species Variorum

→ in their heart and system of circulation, 1866

circulating system, 1869 1872

→ with which their stomachs, equally complicated in both cases, are lined, 1866

with which their complex stomachs are lined, 1869

within their complex stomachs, 1872

→ water-breathing 1866

whole structure of the water-breathing 1869 1872

→ from mere analogy that the equally important air-breathing apparatus would have been the same 1866

that the equally important air-breathing apparatus would have been the same 1869

that 1872

→ are thus furnished; and this might 1866

live on the land; and this might 1869

live on the land, the equally-important air-breathing apparatus would 1872

→ more confidently expected by those who believe in the creation of each separate species; 1866

more confidently expected by those who believe in distinct creations; 1869

same; 1872

→ to a few species which are so closely similar or rather identical in all 1866

to these species, have been made to differ, whilst all the 1869

have been made to differ, whilst all the other important organs were closely similar or rather identical. 1872

→ points, have been made to differ? 1866

OMIT 1872

organs are closely similar or rather identical. 1869

→ the main body of crustaceans of all orders, 1866

most crustaceans of all orders, 1869

most other crustaceans, 1872

→ in each he found it to differ in 1866 1869

he found it to differ in each in 1872

↑ 3 blocks not present in 1859 1860 1861 1866; present in 1869 1872

Now such differences are intelligible, and might even have been anticipated, on the supposition that species belonging to distinct families had slowly become adapted to live more and more out of water, and to breathe the air. For these species, from belonging to distinct families, would differ to a certain extent, and in accordance with the principle that the nature of each variation depends on two factors, viz. the nature of the organism and that of the conditions, the variability of these crustaceans assuredly would not have been exactly the same. Consequently natural selection would have had different materials or variations to work on, in order to arrive at the same functional result; and the structures thus acquired would almost necessarily have differed.

their sense-organs, →in their heart and system of circulation, in the position of

the

every

tufts

tuft

of hair →with which their stomachs, equally complicated in both cases, are lined, and lastly in the →water-breathing branchiæ, even to the microscopical hooks by which they are cleansed. Hence it might have been expected →from mere analogy that the equally important air-breathing apparatus would have been the same in the few species

belonging to

both families which →are thus furnished; and this might have been the →more confidently expected by those who believe in the creation of each separate species; for why should this one apparatus, given for the same

~~special~~

special

purpose,

purpose

→to a few species which are so closely similar or rather identical in all

~~other~~

other

~~important~~

important

→points, have been made to differ?

Fritz Müller

~~then~~

then

argues

argued

~~to himself~~

to himself

that this close similarity in so many points of structure must, in accordance with the views advanced by me, be accounted for by inheritance from a common progenitor. But as the vast majority of the species in the above two families, as well as →the main body of crustaceans of all orders, are aquatic in their habits, it is improbable in the highest degree, that their common progenitor should have been adapted for breathing air. Müller was thus led carefully to examine

~~and describe~~

and describe

the apparatus in the

~~few~~

few

air-breathing species; and →in each he found it to differ in several important points, as in the position of the orifices, in the manner in which they are opened and closed, and in some accessory details. ↑ Now, on the belief that species belonging to distinct families, already differing in some characters, and which whenever they varied would probably have varied in different manners, have been slowly adapted through natural selection to live more and more out of water and to breathe the air, it is quite intelligible, and might even have been con-