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Updated: May 16, 2025
One specimen of Plaice of this type was kept alive in the aquarium, and it lay on its side, buried itself in the sand, and when disturbed swam horizontally, like a normal specimen. The abnormalities are undoubtedly mutations of gametic origin.
I marked the deepenings of the shade, and the mutations which every object successively underwent. The vale was narrow, and hemmed in on all sides by lofty and precipitous cliffs. The gloom deepened as the moon declined, and the faintness of starlight was all that preserved my senses from being useless to my own guidance. I drew nearer the cleft at which this mysterious personage had entered.
The evolution of the normal Flat-fish, on the other hand, was obviously due to a change of a different kind. Here we are dealing with the change from a symmetrical fish to the asymmetrical. Judging from what takes place in other mutations, it was quite possible for asymmetry to have developed directly from the egg, in consequence of some difference in the chromosomes of the nucleus. Eut.
Has it been created? or has it arisen by the power of natural causation? If the former hypothesis is correct, then the axiom, "ex nihilo nihil fit," is false, even in relation to the ordinary course of nature, seeing that such mutations of matter as imply the continual origin of new substantial forms are occurring every moment.
It was probable that a chink had remained open, sufficient to indicate its existence to Bridgenorth; who withdrawing it altogether, had found his way into the secret apartment with which it communicated, and from thence to the postern of the Castle by another secret passage, which had been formed in the thickness of the wall, as is not uncommon in ancient mansions; the lords of which were liable to so many mutations of fortune, that they usually contrived to secure some lurking place and secret mode of retreat from their fortresses.
Just as Napoleon was transformed by the mutations of his pituitary, so was the Saint with the Lamp. And in both instances the contrasting modifications, from one extreme of glandular function to the other, supply us with the clue to the secret hand of their inner being and becoming, which worked upon the twists and turns of circumstance about them as a sculptor upon clay.
But no such proof has been found, and the conclusion seems admissible that the mutation of toad-flaxes ordinarily, if not universally, takes place by a sudden step. Our experiment may simply be considered as a thoroughly controlled instance of an often recurring phenomenon. It teaches us how, in the main, the peloric mutations must be assumed to proceed. This conception may still be broadened.
Here we may assume that the old Draba verna has produced a host or a swarm of new types. Thence they must have spread over Europe, but whether in doing so they have remained constant, or whether some or many of them have repeatedly undergone specific mutations, is of course unknown.
For many years past I have tried to elucidate the hereditary conditions of species and varieties, and the occasional occurrence of mutations, that suddenly produce new forms. The present discussion has a double purpose. On one side it will give the justification of the theory of mutations, as derived from the facts now at hand.
One day was so much like another, too, in that tranquil season of the year, and in that luxurious sea, that all on board knew the regular mutations that the hours produced. The southerly air in the morning, the zephyr in the afternoon, and the land wind at night, were as much matters of course as the rising and setting of the sun.
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