For about six weeks we had magnificent weather--clear, sunny skies, and calm seas; and I greatly enjoyed my evening rambles amid the hills, or along the sea-shore. I was struck, in these walks, by the amazing abundance of the wild flowers which covered the natural meadows and lower hill-slopes--an abundance, as I have since remarked, equally characteristic of both the northern and western islands of Scotland. The lower slopes of Gairloch, of western Sutherland, of Orkney, and of the northern Hebrides generally--though, for the purposes of the agriculturist, vegetation languishes, and wheat is never reared--are by many degrees richer in wild flowers than the fat loamy meadows of England. They resemble gaudy pieces of carpeting, as abundant in petals as in leaves. Little of the rare is to be detected in these meadows, save, perhaps, that in those of western Sutherland a few Alpine plants may be found at a greatly lower level than elsewhere in Britain; but the vast profusion of blossoms borne by species common to almost every other part of the kingdom, imparts to them an apparently novel character. We may detect, I am inclined to think, in this singular floral profusion, the operation of a law not less influential in the animal than the vegetable world, which, when hardship presses upon the life of the individual shrub or quadruped, so as to threaten its vitality, renders it fruitful on behalf of its species. I have seen the principle strikingly exemplified in the common tobacco plant, when reared in a northern country, in the open air. Year after year it continued to degenerate, and to exhibit a smaller leaf and shorter stem, until the successors of what in the first year of trial had been rigorous plants, of some three to four feet in height, had in the sixth or eighth become mere weeds, of scarce as many inches. But while the as yet undegenerate plant had merely borne atop a few florets, which produced a small quantity of exceedingly minute seeds, the stunted weed, its descendant, was so thickly covered over in its season with its pale yellow bells, as to present the appearance of a nosegay; and the seeds produced were not only bulkier in the mass, but also individually of much greater size. The tobacco had grown productive in proportion as it had degenerated. In the common scurvy-grass, too--remarkable, with some other plants for taking its place among both the productions of our Alpine heights and of our sea-shores--it will be found that, in proportion as its habitat proves ungenial, and its leaves and stems become dwarfish and thin, its little white cruciform flowers increase, till, in localities where it barely exists, as if on the edge of extinction, we find the entire plant forming a dense bundle of seed vessels, each charged to the full with seed. And in the gay meadows of Gairloch and Orkney, crowded with a vegetation that approaches its northern limit of production, we detect what seems to be the same principle chronically operative; and hence, it would seem, their extraordinary gaiety. Their richly blossoming plants are the poor productive _Irish_ of the vegetable world; for Doubleday seems quite in the right in holding that the law extends to not only the inferior animals, but to our own species also. The lean, ill-fed sow and rabbit rear, it has been long known, a greatly more numerous progeny than the same animals when well cared for and fat; and every horse and cattle breeder knows that to over-feed his animals proves a sure mode of rendering them sterile. The sheep, if tolerably well pastured, brings forth only a single lamb at a birth; but if half-starved and lean, the chances are that it may bring forth two or three. And so it is also with the greatly higher human race. Place them in circumstances of degradation and hardship so extreme as almost to threaten their existence as individuals, and they increase, as if in behalf of the species, with a rapidity without precedent in circumstances of greater comfort. The aristocratic families of a country are continually running out; and it requires frequent creations to keep up the House of Lords; whereas our poorer people seem increasing in more than the arithmetical ratio. In Skye, though fully two-thirds of the population emigrated early in the latter half of the last century, a single generation had scarce passed ere the gap was completely filled; and miserable Ireland, as it existed ere the famine, would have been of itself sufficient, had the human family no other breeding-place, to people in a few ages the world.