Origin of Species Variorum

→ OMIT 1861 1866 1869 1872

(whose numbers are probably regulated by hawks or beasts of prey) 1859 1860

→ parasitic insects would probably increase; 1861 1866 1869 1872

flies would decrease— then cattle and horses would become feral, 1859

flies would decrease— then cattle and horses would became feral, 1860

→ lessen the number of the navel-frequenting flies— then cattle and horses would become feral, and this would certainly 1861 1866 1872

certainly 1859 1860

lessen the number of the navel-frequenting flies—then cattle and horses would become feral, and this would certainly 1869

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

We began this series by insectivorous birds, and we have ended with them.

→ for long periods of time uniform, 1872

uniform for long periods of time, 1859 1860 1861 1866 1869

→ OMIT 1872

in this part of England, 1859 1860 1861 1866 1869

→ in my garden by 1872

by 1859 1860 1861 1866 1869

→ find from experiments 1861 1866 1869 1872

have, also, reason to believe 1859 1860

→ whether they could do so 1869 1872

this 1861 1866

→ not being 1869 1872

being apparently not 1861 1866

→ we may infer as highly probable 1861 1866 1869 1872

I have very little doubt, 1859 1860

insectivorous birds →OMIT were to

increase

decrease

in Paraguay, the →parasitic insects would probably increase; and this would →lessen the number of the navel-frequenting flies— then cattle and horses would become feral, and this would certainly greatly alter (as indeed I have observed in parts of South America) the vegetation: this again would largely affect the insects; and this, as we

just have

have just

seen in

Stafford-shire,

Staffordshire,

the insectivorous birds, and so onwards in ever-increasing circles of complexity. ↑ Not that

under

nature the relations

can

will

ever be as simple as this. Battle within battle must

ever

....

recurring

continually recurring

with varying success; and yet in the long-run the forces are so nicely balanced, that the face of nature remains →for long periods of time uniform, though assuredly the merest trifle would

often

....

give the victory to one organic being over another.

Nevertheless

Nevertheless,

so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world, or invent laws on the duration of the forms of life!

I am tempted to give one more instance showing how plants and animals,

most

....

remote in the scale of nature, are bound together by a web of complex relations. I shall hereafter have occasion to show that the exotic Lobelia

fulgens,

fulgens

→OMIT is never visited →in my garden by insects, and consequently, from its peculiar structure, never

can

....

set

sets

a seed.

Many of

Nearly all

our orchidaceous plants absolutely require the visits of

moths

insects

to remove their pollen-masses and thus to fertilise them. I →find from experiments that humble-bees are

indispensable

almost indispensable

to the fertilisation of the heartsease (Viola tricolor), for other bees do not visit this flower. I have also found that the visits of bees are necessary for the fertilisation of some kinds of clover: for instance, 20 heads of Dutch clover (Trifolium repens) yielded 2,290

seeds;

seeds,

but 20 other heads protected from bees produced not one. Again, 100 heads of red clover (T. pratense)

pro- duced

produced

2,700 seeds, but the same number of protected heads produced not a single seed. Humble-bees alone visit red clover, as other bees cannot reach the nectar. It has been suggested that moths may

serve to

....

fertilise the clovers; but I doubt →whether they could do so in the case of the red clover, from their weight →not being sufficient to depress the

wing-petals.

wing petals.

Hence →we may infer as highly probable

that

that,

if the whole genus of humble-bees became extinct or very rare in England, the heartsease and red clover would become very rare, or wholly disappear. The number of humble-bees in any district depends in a great

degree

measure

on the number of field-mice, which destroy their combs and nests; and

Mr. H.

Col.

Newman, who has long attended to the habits of