There is one fact, however, here to be observed, which is very well worthy of attention; and this is, that coloured varieties appear to have been chiefly produced in hot countries; which seems almost to induce the conclusion that they were originally efforts of nature, to enable the skin to withstand the scorching produced by exposure to the burning rays of a tropical sun.¹⁰  How far the structural peculiarities of the Negro and other races may not, in some cases, be the effects of breed, it would be impossible, perhaps, now to ascertain, and would be worse than presumption, in a novice like myself, to try to determine.
   Wherever a black individual was produced, especially among rude nations, if the breed was continued at all, the natural aversion it would certainly inspire would soon cause it to become isolated, and, before long, would, most probably, compel the race to seek for refuge in emigration.  That no example, however, of the first production of a black variety has been recorded, may be ascribed to various causes; it may have only taken place once since the creation of the human race, and that once in a horde of tropical barbarians remote from the then centres of comparative civilisation, where no sort of record would have been preserved.  But it is highly probable that analogous-born varieties may have given rise to the Mongolian, Malay, and certain others of the more diverse races of mankind; nay, we may even suppose that, in some cases, the difference, in the first instance, was much greater, and was considerably modified by the intermixture which must have taken place in the first generations.
   The mixed offspring of two different varieties of man thus generally blends the characters of each; though instances are not wanting of its entirely resembling (like the mixed produce of an ancon sheep) either one or the other of its parents; but in this case (as in the albino) the perfect characters of the other parent frequently show themselves in the next generation. I am entering, however, into a wide field, already well trodden by many philosophers; and the subject is already probably pretty well understood by the great majority of readers.  Those who are not so familiar with it, will find it ably treated in various works; especially in Dr. Pritchard's work on man, and in the published Lectures on the Natural History of Man, by Lawrence: some sound and excellent remarks on varieties will also be found in the second volume of Lyell's Principles of Geology.

Still, however, it may not be impertinent to remark here, that, as in the brute creation, by a wise provision, the typical characters of a species are, in a state of nature, preserved by those individuals chiefly propagating, whose organisation is the most perfect, and which, consequently, by their superior energy and physical powers, are enabled to vanquish and drive away the weak and sickly, so in the human race degeneration is, in great measure, prevented by the innate and natural preference which, and this is the principal and is always given to the most comely main reason why the varieties which are produced in savage tribes, must generally either become extinct in the first generation, or, if propagated, would most likely be left to themselves, and so become the origin of a new race; and in this we see an adequate cause for the obscurity in which the origin of different races is involved.
   In a civilised state of society there are other inducements, besides personal attractions, and a new variety in this case, unless very outre indeed, would be gradually merged, and in a few generations would disappear entirely by intermixture with the common race.  The inferior animals appear not to have the slightest predilection for superior personal appearance; the most dissimilar varieties of the same species mix as freely and readily together as the most typical individuals; the most powerful alone becomes the favourite. Instances of this are not rare in the breeds of dogs.

The above is confessedly a hasty and imperfect sketch, a mere approximation towards an apt classification of "varieties", but if it chance to meet the eye, and be fortunate enough to engage the attention, of any experienced naturalist, who shall think it worth his while to follow up the subject, and produce a better arrangement of these diversities, my object in indicting the present article will be amply recompensed.
   Here, however, I may observe, that the classification I have proposed for specific deviations in the animal creation, is equally applicable to those of the vegetable.  The "varieties" in both are strictly analogous.

I come now to the second division of my subject, which is to point out some periodical and other changes of appearance, which naturally take place in various British animals, and which do not constitute varieties.  Among our native Mammalia, I know of three principal modes whereby a change of colour is brought about; namely, an actual shedding of the coat; a partial shedding of the coat; and an actual change of colour in the coat itself.

1. As an example of change of appearance produced by actual shedding of the coat, may be instanced the fallow deer (Cervus dama), whose white spots disappear with the annual casting of its coat in autumn.
2. Partial shedding of the coat takes place in those animals which acquire in autumn a covering of two different kinds: one long, downy, and warm, which is shed in spring; the other short and glossy, which is retained.  This change of appearance is exemplified in the common water shrew (Sorex fodiens), the short summer coat of which is much blacker than the longer downy covering which conceals this in winter.
      In this little animal the additional winter coat is shed about the latter end of March, or beginning of April; and does not take place uniformly, but progressively, beginning on the head, and ceasing at the hinder extremities; and exhibiting in its progress, throughout, a well-defined line of separation.  Animals which (as the British Mustelinae) have two sorts of fur, the shorter of which is the more warm and downy, do not undergo this change, but retain both sorts throughout the year. In these the young have only one kind, which is close and woolly. as is well exemplified in the common polecat (Putorius furc), the young of which are of a very uniform dark brown, and very unlike the old animals.
3. Actual change of colour in the coat itself is exhibited in the appearance of the fallow deer's white spots in spring, and in the case of the mountain hare (Lepus variabilis), which is in summer grey, adapted to the hue of the lichens on which it squats; and in winter white, hardly to be discerned upon the snow.  The same change also takes place in the stoat or ermine (Putorius ermineus), although this is doubted by Mr. Berry [VII, 591].¹¹
      In mild winters, such as we have of late experienced in the South of England, but few of the stoats become white, and some of these not until the latter part of the season.  The change takes place quickly, but not uniformly, the animal assuming for a short time a pied appearance; but I have not succeeded in ascertaining whether it is accelerated by sudden cold, as the animals are not always to be seen exactly when we want them.  One perfectly changed, however, was seen in this neighbourhood soon after the one or two days of very cold weather in the beginning of last October.  In reference to Mr. Berry's communication, I may observe, that in many dozens of stoats which I have seen in summer, I have never yet seen a white one; whereas in winter, I have seen in the same neighbourhoods a considerable number of white stoats.  Where the climate is excessive, and the transitions of the seasons are more sudden, this change is much more likely to take place generally.  In the fur countries, the ermine's change of hue is, I believe, most regular.

It would indeed be easy to extend this list of examples considerably further, but I shall only now mention the common hare, which, when in form, would hardly ever be seen were it not for its brilliant eye; if its eye were closed, which it probably was before its quick sense of hearing had warned it of our approach, it would almost always, perhaps, wholly escape our observation.  This ever continued watchfulness must have given rise to the supposition, that the hare always sleeps with its eyes open.
   Seeing, therefore, so many most striking adaptations of colour to haunt, in cases where the concealment thus afforded can be the only purpose, I think it is not too much to infer, that the changes of colour in many arctic animals were intended by Providence for the double purpose of preserving their bodily heat, and of enabling them to elude the observation of their enemies.  Certain it is, that their conspicuousness would otherwise expose them to inevitable destruction.  If I had here space, I could satisfactorily prove that the high-flying Falconidae can, in most cases, only perceive their prey when it is moving; just, as on the seashore, we can only distinguish sanderlings when they move.
   Small Mammalia which frequent open situations are rarely much abroad, except in the twilight; and ground-feeding birds are ever on the watch, and even the smaller kinds (as I have repeatedly observed) can perceive a hovering falcon long before it comes within the sphere of human vision; and they instantly flee to shelter, or they crouch, and lying motionless, so exactly resemble a portion of the surface, that even a hawk's eye cannot distinguish them.  Why should the falcon race be endowed with such wonderful powers of enduring hunger and fatigue, if, as is said, at the elevations at which they soar, they can clearly distinguish every living object scattered over the wide expanse beneath them?  It is only on such animals as are off their guard that they descend; or otherwise, food being so abundant, they would soon multiply to the extirpation of their prey; which, of course, would be very speedily followed by that of the preyer.

How beautifully do we thus perceive, as in a thousand other instances, the balance of nature preserved: and even here we see another reason why sickly or degenerate animals (those, I mean, which are less able to maintain the necessary vigilance) must soon disappear; and why the slightest deviation from the natural hue must generally prove fatal to the animal.  How different, thus, are even simple variations from the seasonal changes of colour which naturally take place!  Properly followed up, this subject might lead to some highly interesting and important results.
   It certainly points to the conclusion, that every, even the slightest, tint and marking has some decided use, and is intimately connected with the habits and welfare of the animal; and it also furnishes a satisfactory reason, why closely allied animals (or, in other words, animals of very similar form and habits) should so very commonly nearly resemble each other in their colours and in the general character of their markings.