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05 - Laws of Variation 05-12 - Reversion to Long Lost Characters 30 A considerable catalogue, also, could be given of forms intermediate between two other forms, which themselves can only doubtfully be ranked as species; and this shows, unless all these closely allied forms be considered as independently created species, that they have in varying assumed some of the characters of the others.

But the best evidence of analogous variations is afforded by parts or organs which are generally constant in character, but which occasionally vary so as to resemble, in some degree, the same part or organ in an allied species.

I have collected a long list of such cases; but here, as before, I lie under the great disadvantage of not being able to give them.

I can only repeat that such cases certainly occur, and seem to me very remarkable.
14 - Recapitulation and Conclusion 14-05 - Effects of its adoption on the study of Natural history 30 A new variety raised by man will be a far more important and interesting subject for study than one more species added to the infinitude of already recorded species.

Our classifications will come to be, as far as they can be so made, genealogies; and will then truly give what may be called the plan of creation.

The rules for classifying will no doubt become simpler when we have a definite object in view.

We possess no pedigrees or armorial bearings; and we have to discover and trace the many diverging lines of descent in our natural genealogies, by characters of any kind which have long been inherited.

Rudimentary organs will speak infallibly with respect to the nature of long-lost structures.

Species and groups of species, which are called aberrant, and which may fancifully be called living fossils, will aid us in forming a picture of the ancient forms of life.
12 - Geographical Distribution -- continued 12-40 - On the relations of the inhabitants of islands to those of the nearest mainland 30 All the foregoing remarks on the inhabitants of oceanic islands, namely, the scarcity of kinds -- the richness in endemic forms in particular classes or sections of classes, the absence of whole groups, as of batrachians, and of terrestrial mammals notwithstanding the presence of aerial bats, the singular proportions of certain orders of plants, herbaceous forms having been developed into trees, &c., seem to me to accord better with the view of occasional means of transport having been largely efficient in the long course of time, than with the view of all our oceanic islands having been formerly connected by continuous land with the nearest continent; for on this latter view the migration would probably have been more complete; and if modification be admitted, all the forms of life would have been more equally modified, in accordance with the paramount importance of the relation of organism to organism.

I do not deny that there are many and grave difficulties in understanding how several of the inhabitants of the more remote islands, whether still retaining the same specific form or modified since their arrival, could have reached their present homes.

But the probability of many islands having existed as halting-places, of which not a wreck now remains, must not be overlooked.

I will here give a single instance of one of the cases of difficulty.

Almost all oceanic islands, even the most isolated and smallest, are inhabited by land-shells, generally by endemic species, but sometimes by species found elsewhere.

Land Shell
Land Shell


Dr. Aug. A. Gould has given several interesting cases in regard to the land-shells of the islands of the Pacific.

Augustus Addison Gould
Augustus Addison Gould

Pacific Ocean
Pacific Ocean


Now it is notorious that land-shells are very easily killed by salt; their eggs, at least such as I have tried, sink in sea-water and are killed by it.

Yet there must be, on my view, some unknown, but highly efficient means for their transportal.

Would the just-hatched young occasionally crawl on and adhere to the feet of birds roosting on the ground, and thus get transported? It occurred to me that land-shells, when hybernating and having a membranous diaphragm over the mouth of the shell, might be floated in chinks of drifted timber across moderately wide arms of the sea.

And I found that several species did in this state withstand uninjured an immersion in sea-water during seven days: one of these shells was the Helix pomatia, and after it had again hybernated I put it in sea-water for twenty days, and it perfectly recovered.

Helix Pomatia
Helix Pomatia


As this species has a thick calcareous operculum, I removed it, and when it had formed a new membranous one, I immersed it for fourteen days in sea-water, and it recovered and crawled away: but more experiments are wanted on this head.
01 - Variations Under Domestication 01-08 - Breeds of the Domestic Pigeons, their Differences and Origin 30 Altogether at least a score of pigeons might be chosen, which, if shown to an ornithologist, and he were told that they were wild birds, would certainly be ranked by him as well-defined species.

Moreover, I do not believe that any ornithologist would in this case place the English carrier, the short-faced tumbler, the runt, the barb, pouter, and fantail in the same genus; more especially as in each of these breeds several truly-inherited sub-breeds, or species, as he would call them, could be shown him.

English Carrier Pigeon
English Carrier Pigeon

Short Faced Tumbler Pigeon
Short Faced Tumbler Pigeon

Runt Pigeon
Runt Pigeon

Barb Pigeon
Barb Pigeon

Pouter Pigeon
Pouter Pigeon

Fantail Pigeon
Fantail Pigeon