Origin of Species Variorum

→ probably, habit and selection have 1859 1860 1861 1866

habit and selection have probably 1869

habit and selection have 1872

→ three, out of the several which I shall have to discuss in my future work,— 1859 1860 1861 1866

three, out of those which I shall have to discuss in my future work,— 1869

three,— 1872

→ Cuckoo. — 1866

Cuckoo . — 1869

Cuckoo — 1872

→ now commonly admitted 1859 1860 1861 1866

supposed by some naturalists 1869 1872

→ most remarkable of the instincts of the cuckoo 1866

cuckoo's instinct 1859 1861

cuckoos instinct 1860

instinct of the cuckoo 1869 1872

→ nest. 1859 1860 1861 1866 1872

nest. If this were the case, the process of laying and hatching might be inconveniently long, more especially as she migrates at a very early period; and the first hatched young would probably have to be fed by the male alone. 1869

for the mother-hen has almost lost by disuse the power of flight.

Hence, we may conclude, that

domestic

under domestication

instincts have been

acquired

acquired,

and natural instincts have been

lost

lost,

partly by habit, and partly by man selecting and

accumulating

accumulating,

during successive generations, peculiar mental habits and actions, which at first appeared from what we must in our ignorance call an accident. In some cases compulsory habit alone has sufficed to produce

~~such~~

such

inhe- rited

inherited

mental changes; in other cases compulsory habit has done nothing, and all has been the result of selection, pursued both methodically and

unconsciously:

unconsciously;

but in most

cases

cases,

→probably, habit and selection have

probably concurred.

acted together.

Special

Instincts .

Instincts.

We shall, perhaps, best understand how instincts in a state of nature have become modified by selection, by considering a few cases. I will select only →three, out of the several which I shall have to discuss in my future work,— namely, the instinct which leads the cuckoo to lay her eggs in other

birds

birds'

nests; the slave-making instinct of certain ants; and the

cell-making

comb-making

power of the

hive-bee;

hive-bee.

hive-bee:

These

these

two latter instincts have

generally

generally,

and

~~most~~

most

justly

justly,

been ranked by naturalists as the most wonderful of all known instincts.

Instincts

the

→ Cuckoo. —

It is →now commonly admitted that the more immediate

~~and final~~

and final

cause of the →most remarkable of the instincts of the cuckoo is, that she lays her eggs, not daily, but at intervals of two or three days; so that, if she were to make her own nest and sit on her own eggs, those first laid would have to be left for some time unincubated, or there would be eggs and young birds of different ages in the same →nest. If this were the case, the process of laying and hatching might