Origin of Species Variorum

→ animal, by some modification of its structure, for 1859 1860 1861 1866

structure of the animal to 1869 1872

→ But it is 1859 1860 1861 1866

It is, however, 1869 1872

→ like 1859 1860 1861

into it like 1866 1869 1872

states

between structures fitted for very different habits of life will rarely have been developed at an early period in great numbers and under many subordinate forms. Thus, to return to our imaginary illustration of the

flying-fish;

flying-fish,

it does not seem probable that fishes capable of true flight would have been developed under many subordinate forms, for taking prey of many kinds in many ways, on the land and in the water, until their organs of flight had come to a high stage of perfection, so as to have given them a decided advantage over other animals in the battle for life. Hence the chance of discovering species with transitional grades of structure in a fossil condition will always be less, from their having existed in lesser numbers, than in the case of species with fully developed structures.

I will now give two or three instances

both of

diversified and of changed habits in the individuals of the same species.

When

either case

~~occurs,~~

occurs,

it would be easy for natural selection to

adapt

fit

the →animal, by some modification of its structure, for its changed habits, or exclusively

for

one of its several

~~different~~

different

habits. →But it is difficult to

decide,

tell,

and immaterial for us, whether habits generally change first and structure afterwards; or whether slight modifications of structure lead to changed habits; both probably often

occurring

change

almost simultaneously. Of cases of changed habits it will suffice merely to allude to that of the many British insects which now feed on exotic plants, or exclusively on artificial substances. Of diversified habits innumerable instances could be given: I have often watched a tyrant flycatcher (Saurophagus sulphuratus) in South America, hovering over one spot and then proceeding to another, like a kestrel, and at other times standing stationary on the margin of water, and then dashing →like a kingfisher at a fish. In our own country the larger titmouse (Parus major) may be