Origin of Species Variorum

→ various 1859 1860 1861 1866

to the various 1869 1872

→ this has been the universal 1859 1860 1861 1866

a single birthplace is the 1869 1872

→ on my theory have all 1859 1860 1861 1866

must on the theory all be 1869

must on our theory all be 1872

could have passed from one point to the other. But the geographical and climatal changes, which have certainly occurred within recent geological times, must have

~~interrupted or~~

interrupted or

rendered discontinuous the

for- merly

formerly

continuous range of many species. So that we are reduced to consider whether the exceptions to continuity of range are so numerous and of so grave a nature, that we ought to give up the belief, rendered probable by general considerations, that each species has been produced within one area, and has migrated thence as far as it could. It would be hopelessly tedious to discuss all the exceptional cases of the same species, now living at distant and separated

points,

points;

nor do I for a moment pretend that any explanation could be offered of many

instances.

such cases.

But,

But

after some preliminary remarks, I will discuss a few of the most striking classes of facts; namely, the existence of the same species on the summits of distant mountain-ranges, and at distant points in the arctic and antarctic regions; and secondly (in the following chapter), the wide distribution of

freshwater

fresh-water

productions; and thirdly, the occurrence of the same terrestrial species on islands and on the

nearest mainland,

mainland,

though separated by hundreds of miles of open sea. If the existence of the same species at distant and isolated points of the

earths

earth's

surface, can in many instances be explained on the view of each species having migrated from a single birthplace; then, considering our ignorance with respect to former climatal and geographical changes and →various occasional means of transport, the belief that →this has been the universal law, seems to me incomparably the safest.

In discussing this subject, we shall be enabled at the same time to consider a point equally important for us, namely, whether the several

~~distinct~~

distinct

species of a genus, which →on my theory have all descended from a common