See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1866
1872

Comparison with 1859

conceive by what steps these wondrous organs have been produced; but, as Owen and others have remarked, their intimate structure closely resembles that of common muscle; and as it has lately been shown that Rays have an organ closely analogous to the electric apparatus, and yet do not, as Matteuchi asserts, discharge any electricity, we must own that we are far too ignorant to argue that no transition of any kind is possible.
The electric organs offer another and even more serious difficulty; for they occur in only about a dozen fishes, of which several are widely remote in their affinities. Generally when the same organ appears in several members of the same class, especially if in members having very different habits of life, we may attribute its presence to inheritance from a common ancestor; and its absence in some of the members to its loss through disuse or natural selection. But if the electric organs had been inherited from one ancient progenitor thus provided, we might have expected that all electric fishes would have been specially related to each other. Nor does geology at all
conceive by what steps these wondrous organs have been produced. As Owen has remarked, there is much analogy between them and ordinary muscles, in their manner of action, in the influence on them of the nervous power and of stimulants such as strychnine, and as some believe in their intimate structure. We do not even ... know of what use these organs are; though in the Gymnotus and Torpedo they no doubt serve as powerful means of defence and perhaps for securing prey; yet in the Ray an analogous organ in the tail, even when greatly irritated, manifests, as lately observed by Matteucci, but little electricity; so little that it can hardly be of .. use for such purposes. Moreover, in the Ray, besides the organ just referred to, there is, as Dr. R. M'Donnell has shown, another organ near the head, not known to be electrical, but which appears to be the real homologue of the electric battery in the torpedo. .. Lastly, as we know nothing about the lineal progenitors of .. these fishes, it must be admitted that we are too ignorant to be enabled to affirm that no transitions are possible, through which the electric organs might have been developed.
These same organs at first appear to offer another and far more serious difficulty; for they occur in .. about a dozen kinds of fish, of which several are widely remote in their affinities. Generally when the same organ is found in several members of the same class, especially if in members having very different habits of life, we may attribute its presence to inheritance from a common ancestor; and its absence in some of the members to .. loss through disuse or natural selection. So that, if the electric organs had been inherited from some one ancient progenitor, .. we might have expected that all electric fishes would have been specially related to each other; but this is far from the case. Nor does geology at all