to find them there), but species of the same families and of the same genera, and, more than that, species very closely allied in form and appearance. It may be said, it is easy to argue from an if; but I think here I am able to offer something more than an if. No doubt the northern Arctic shores which I have instanced are not widely separated from each other; but I am able to refer to instances of places widely separated presenting conditions as nearly as possible identical, and producing species correspondingly similar. The first case is that of the blind cave animals found in the caves of Europe and Kentucky. Here, in a nearly corresponding latitude, yet in position separated by half the globe, are caves extending for miles into the bowels of the earth; and far in the interior of these caves, where impenetrable darkness and everlasting silence reign, living eyeless creatures are foundmore particularly a number of different kinds of insects. The number of genera and different forms yet known is few, but the number of species is considerable-almost every freshly examined cave furnishing something new. Now, the extraordinary thing is, not only that, in the different caves in Europe, the new species found in almost every fresh cave belong to already known cave genera,† but that the species found in Kentucky also belong to the same genera. The first species discovered there was Anophthalmus Tellkampfii, which so exactly corresponds in form and appearance to the European species, A. Schmidtii or A. Bilimekii, that any one but an entomologist would say they were the same. Adelops hirtus and Adelops Tellkampfii have since been found; and, in their turn, they so exactly resemble the Carniolan species Adelops Milleri and Adelops Freyeri, that the same may be said of them. Here, according to my view, the creative influence, acting under the same conditions, produces the same results—that is, produces creatures as nearly identical as can be without being the same. Nature never repeats

* Schiodte says of the Carniolan caves, that the blind insects are not found until about two miles from the mouth of the cave.

†The cave genera are, with one exception, confined to caves ;-the one exception is the genus Adelops, of which some blind species are found, not in caves, but in dark places, under moss, &c.

herself; and we could not, therefore, expect the very same. And the inference I draw receives a double confirmation from the fact, that a great many of the European caves may be viewed as thoroughly isolated, and as free from communication as the Kentucky from the Carniolan; and I know of instances in which the inhabitants of such caves are not specifically distinct -the Auvergne species from the Pyrenean, the Pyrenean from the Carniolan, and so on. I may therefore say, that in the case of these caves we have a subterranean region as distinct and well defined as any purely geographical region in the upper world. Whether we may find other species of Anophthalmus or Adelops in the caves of Australia, or in caves yet to be discovered in tropical countries, is another question, and one which would not necessarily much affect the view I have taken, even although the species which might there be found should belong to new genera; for, in the first place, there may be more genera yet to be discovered in Europe—(I have no doubt there are)—and already we know several European genera which have not been found in America, and the converse may in all probability be yet found to be the case with regard to America; so that the mere discovery of a new form would go for nothing-the rather that our knowledge of the fauna of the subterranean region is as yet too limited to allow us to say whether a new form bears its facies or not; and, in the second place, the temperature, or, what is still more likely to affect the fauna of caves, the degree of moisture, may be sufficient to constitute a different class of subterranean region. The European and American is a wet subterranean, the Australian may very probably be a dry one; but if it should prove not to have different conditions, I then should most confidently look for the occurrence in them of new species of the European genera, Anophthalmus and Adelops.

Another region, sui generis, may be adduced as possessing in a certain, though less marked degree, special conditions of life under which similar peculiar forms have been evolved in distant countries, viz.-the interior of ants' nests. As already said, entomologists have of late years found many Coleopterous insects, not met with elsewhere, in the interior of ants' nests. Some of these (the Clavigeri, the Formicosomi, &c.) are invested

with the outward appearance of the ants among which they live; others have no special resemblance to their hosts; but the point to which I press attention here is, that the true ant-nest species are found in ants' nests, and nowhere else; that a peculiar facies (in many cases a peculiar structure) belongs to most of them, probably to all which exclusively inhabit ants' nests. The search into ants' nests for these exceptional Coleoptera has been carried on very keenly for some years past in Europe, but as yet little has been done in foreign countries. The little that has been done has furnished very interesting results, and results quite in keeping with the view I have been maintaining. Species of Paussi (a marked genus with an exceptional structure, and believed to be absolutely confined to ants' nests) have been found in Spain, in West Africa, at the Cape, at Natal, in the East Indies, at Hong Kong, in Australia, &c. Researches in North America have likewise shown resemblances to our European species in other less exceptional species found in the ants' nests there. We must remember, however, that such a habitat is less defined and restricted, and more subject to the intrusion of external influences than the other special regions of which we have been speaking. There is another kind of condition allied to the last, also drawn from the insect kingdom, which furnishes another instance in support of my position. I mean the singular coincidence of form and appearance shown by all the species of water-beetles, wherever found. The conditions of life in a piece of water vary little, and we see as little variation in the appearance of its occupants. Entomologists have had their ingenuity exercised in endeavouring to account for the presence of apparently the same species of water-beetle (for instance, Colymbetes notatus) in distant countries-in New Zealand and Great Britain; and I have myself suggested, that the eggs or larvæ may have been transmitted in the water-vessels of ships; but it may be that the species is distinct, only that the characters are too slight to catch our eyes. At any rate, there is no doubt about the fact, that water-beetles are so close in structure to each other as to allow of only a very few genera, the great majority belonging only to a small number of distinct forms; and the chief difference appears to depend upon their

being carnivorous or vegetable feeders. Again, there is a small beetle (Epus fulvescens) found on our shores half-way between high and low water mark, and which certainly passes more than the half of its existence under the sea. There are

two or three others of similar mode of life, but I more particularly refer to this one. Its usual place of abode is between the flat strata or leaves of shale or other foliaceous rock; and it is provided with means of securing and enveloping itself in a sufficient supply of air to last during its submersion, so as to maintain life, and move about unwetted.

On the coast of Chili, a similar small species (Thalassobius testaceus) is found living under the same conditions, and having the same facies as our pus; sufficiently distinct to be made into a separate genus, but a genus taking its place next to Epus.

It may be said, that if my views on this point were really sound, we should in like manner find the fishes and mollusca of our own seas, and of those of Chili, &c., bearing the same type. But this by no means follows; for observe, in the first place, we are here comparing an animal created to suit an abnormal condition with those in a normal condition, and it might be expected that the abnormal condition would express itself more forcibly in any deviation of structure than the normal condition; and, in the second place, we are comparing land animals with sea animals, and we are not entitled to assume that the amount of variation in the condition of life necessary to influence the creative idea in the one is the same as that in the other; or that the same tests indicate the relative amount of variation in condition of life in both. On the contrary, we have every reason to suppose that the reverse is the case-namely, that the creative idea in sea animals was (or is) influenced by a less amount of variation in the conditions of life than in land animals. In all animals and plants, the phenomena of life bear a perfect relation to the phenomena of creation. As already said, the animal created in and bearing the, typical facies of any geographical region, is suited to the conditions of life in that region, and thrives better there than anywhere else; and cannot live at all in regions which are much opposed to its native one. The reindeer could not live in the deserts of

Sahara, nor the lion in the snows of Lapland. In fact, we may say, that where we find one set of phenomena, we shall also find the other. If we find a region of which the flora and fauna are typically peculiar, we shall find that that flora and fauna is not suited, at all events not so well suited, to any other region. They may live in another region which has approximate conditions of life to their own, but will not thrive in it so well as in their own; and however similar the other region may be to it, they will never make their way in it in opposition to its own native fauna and flora, so as to usurp their place. If, therefore, in nature, we find a special fauna confined to a special district, we may assume that the same conditions which influence its restriction to such local habitat also influenced its original creation. Applying this to the question of the relative amount of variation in condition of life necessary to have influenced the phenomena of creation in land and sea animals respectively, we see that if this had been alike in kind and amount, we should have had the same facies in sea animals nearly all over the globe; because temperature and some other particulars, which will suggest themselves of their own accord to the reader (the great difference in the amount of which forms so important a condition of life on land), are so equal all over the sea that they could form no efficient barrier, were their effects no greater there than what they are on land. All the differences that we can detect between one region and another in the sea, would prove no barrier to the passage of most animals on land. We must therefore allow, that the inhabitants of the sea are either more susceptible than land animals (and that both in the phenomena of creation and of life) of the differences in the medium in which they live, or else that there exist in that medium other elements influencing the inhabitants of the sea, which on land do not affect animals, or which we cannot appreciate. If we admit this, we can have little difficulty in suggesting some of the specialties which may have given rise to different marine regions. The difference between the extent of sea and dry land in different parts of the globe, the greater depth and wider extent of the sea in the south, the different distribution of land, the different ingredients of which the shores are composed, combined