and the gryphon-all those mysterious "flitter-winged" fowls that are to be found in the mythland of Lalla Rookh1 and

Such as in idle fantasies do flit,

"ring-birds" and "waker-birds," "fly-birds" and "snow-birds,” "Sultanas" and "Strundt Jagers," and all the rest—

birds

That 'twould have puzzled Adam

To have named.

But as these belong to the pure fauna of fiction, they need no longer reference here. For my concern has been only with the actual feathered things that the poets make use of, and with the manner of the use they make.

I had thought, and so perhaps many may still think, that poets were not merely courtiers of Nature, as naturalists are, but were her Privy Council, her Sanhedrin, her Council of Three. Indeed, I had often read that they were even of a nearer affinity than this. They were "Nature's children," and the great mother loved to unbosom herself to them, and to whisper in their ears secrets that other men or women could not hear, and hearing could not understand. But I now fear this is hardly based on facts. There are, of course, hierarchs who seem to speak with the very voice of Nature herself, but

O how frail

To that large utterance of the early gods

is the language of the majority! They are "mere cuckoos of a poet's thoughts."

PHIL ROBINSON.

1 From Moore's profusion of birds, real and unreal, how aptly his own idea fits his own verse :

So freshly fair

That ne'er hath bird come nigh them,

But from his course through air

Hath been won downward by them.

THE PROBLEMS OF DISTRIBUTION AND THEIR SOLUTION.

H

PART II.

AVING summarised in the preceding article1 the chief facts relating to the distribution of the higher animals on the surface of the globe, and having indicated the boundaries of the six great regions into which, from a consideration of the distribution. of life, the biologist divides the land areas of the earth, we may now enter upon the consideration of the explanations which biology is prepared to afford of the facts in question. It is necessary to bear in mind the cardinal fact that only two theories are possible respecting the distribution of life on the earth; as, indeed only two explanations may be offered concerning any other cosmical phenomena, whether relating to the world of life or to that of inorganic matter. In other words, we must either assume, in the first place, with regard to the distribution of life, or to the origin of species itself, that a supernatural, and therefore inexplicable, fiat in the beginning of things, created each species separately and independently, and placed it directly or indirectly in its special locality or home; or, secondly, we may elect to believe, on the theory of evolution, that the varied tribes of living beings are the descendants of preexisting species; that variation and modification constitute great and continuously operating factors in moulding the living form; that species extend or limit their range of habitat according to the facilities or obstacles presented by their surroundings; and lastly, that physical and geological changes of the earth's surface are continually operating and influencing at once the relations of species, and the character and distribution of the life of any given area. Such are the two hypotheses which now, as of yore, appeal for acceptance, as explanatory of the living universe and its constitution. The first theory is entirely dogmatic and theological in its terms. Stamped by the imprimatur of the churches, it commended itself in a readily understood fashion to

1 See Gentleman's Magazine for July.

the unscientific mind. An exercise of that unquestioning faith which the intellectual mind finds but chains and bondage in its endeavour to rightly interpret the facts of nature in their own light, is all-sufficient to establish the theory of the special creation of animal and plant species in their several localities, as a revelation of Supreme power. But the mind which accepts special creation dare not face nature. There is for such a mind no appeal to the external facts which surround it in the universe of life. There can be no intellectual analysis of belief in such a case; no intelligent questioning of the why and wherefore of the phenomena which the theorist endeavours to explain. The theory of evolution, on the other hand, finds its glory and its strength in its fearless interpretation of nature. There exists no peculiarity of life which it may not seek to explain. It is fettered by no considerations save those which foster reverence for truth, and which make for appreciation of the knowledge that "grows from more to more." Best of all, it has nothing to fear from the advancing tide of knowledge which itself has created and fostered; and it submits its deductions fearlessly and fully to every new light which the increase of research can direct upon them. Sir Joseph Hooker has put the case of Evolution versus Special Creation in the most forcible fashion, when, in speaking of the origin of species, he says: "There are two opinions accepted as accounting for this one, that of independent creation, that species were created under their present form, singly or in pairs or in numbers; the other, that of Evolution, that all are the descendants of one or a few originally created simpler forms. The first doctrine is purely speculative, incapable from its very nature of proof; teaching nothing and suggesting nothing, it is the despair of investigators and inquiring minds. The other, whether true wholly or in part only, is gaining adherents rapidly, because most of the phenomena of plant life may be explained by it; because it has taught much that is indisputably proved.; because it has suggested a multitude of prolific inquiries, and because it has directed many investigators to the discovery of new facts in all departments of Botany." What Sir Joseph Hooker says of evolution in its relations to botanical science may be more than re-echoed by students of distribution. As already remarked, the science of distribution has been actually created by evolution. Before the idea of the modification of species was ventilated, no science which could account for the diverse relationships of living beings in space was possible, because such explanation, on the theory of special creation, was not required. Only, therefore, on the

hypothesis of evolution can any explanation of the distribution of life be attempted. It may be likewise added that, in the facts of distribution, the evolution hypothesis finds one of its strongest supports.

In 1605 appeared a curious work, entitled "The Restitution of Decayed Intelligence in Antiquities, concerning the most noble and renowned English Nation." The author-one Verstegen-informs his readers in one chapter of the reasons for believing that the "Isle of Albion" had been connected by "firm land with Gallia, now named France, since the Flood of Noe." One passage from this quaint work interests exceedingly the student of distribution. It runs as follows: "Another reason there is that this separation hath been made since the Flood, which is also very considerable, and that is the patriarch Noe, having had with him in the ark all sorts of beasts, these then, after the Flood, being put forth of the ark to increase and multiply, did afterward in time disperse themselves over all parts of the continent or mainland; but long after-it could not be before-the ravenous wolf had made his kind nature known to man ; and therefore no man, unless he were mad, would ever transport of that race out of the continent into the isles, no more than men will ever carry foxes (though they be less damageable) out of our continent into the Isle of Wight. But our Isle, as is aforesaid, continuing since the Flood fastened by nature unto the Great Continent, these wicked beasts did of themselves pass over. And if any should object that England hath no wolves on it, they may be answered that Scotland, being therewith conjoined, hath very many; and so England itself some time also had, until such time as King Edgar took order for the destroying of these throughout the whole realm.”

That which to the contemporaries of Verstegen, as to many persons ignorant of the teachings of geology even in our own day, would seem a wild impossibility—namely, the junction of England and France by land-surface-is known to the tyro in geology to have been a plain reality. Convulsions and disconnections, as well as elevations and connections of land-surfaces, are among the most familiar facts of geological science, which views the land as an evershifting quantity amid the factors of physical change.

A brief allusion to some of the more familiar instances in which the association or connection of land-surfaces serves to account for a likeness of the contained life, may demonstrate that the author of "The Restitution of Decayed Intelligence in Antiquities" was, in his day and generation, groping successfully enough after the true cause of the likeness between the animals of Albion and Gaul. In the

Neotropical region of the geologist, the Island of Trinidad presents us with an excellent example of the bearing of geological change over the distribution of life. Geographically, Trinidad is one of the West Indian Islands; zoologically, Trinidad is a part of South America. Whilst the animals of the West Indian Islands are highly peculiar, as we have seen, those of Trinidad resemble the animals found in the neighbouring American area; and along with Trinidad we may class the islands of Tobago, Margarita, and Curaçoa as zoologically belonging to the South American Continent, and not to the Antilles. Close to Trinidad lie Grenada, Barbadoes, and St. Vincent; yet the geographical nearness of these three latter islands to Trinidad is completely overturned by the facts of distribution. What theory of the constitution of living beings and of the earth at large is competent to explain the immense differences which separate Trinidad and neighbouring islets in a zoological sense from the Antilles? On the theory of special creation, no explanation is possible. On the hypothesis of evolution, the main outlines of the problem and its solution are clear enough. The relations of Trinidad and South America are in reality the counterpart of those which Verstegen assumed existed between the "Isle of Albion" and Gaul. At a relatively and geologically "recent" date, there was land connection between Trinidad and the American Continent-such is the geological phase of the question. The biological aspect shows us a sufficient reason for the likeness of the fauna of Trinidad to South American life, by assuming that the processes of variation and change in its species have not yet had time sufficient at their disposal to establish differences of importance. Conversely, the Antilles form, as we have seen, a highly peculiar region for the opposite reason-namely, that these islands, once united to Central America, became detached at a remote period. This ancient separation prevented the inroad of the higher and later forms of life, whilst it would specialise and intensify the characters of the forms which these islands originally claimed as their own.

The case of other islands presents equally and in some cases even more notable and characteristic examples of the influence of isolation from or, conversely, of long-continued connection with continents upon the included life. Very interesting is it to note the extreme differences which prevail between the islands of Bali and Lombok in the Eastern Archipelago, each island being as large as Corsica. They are separated by the Straits of Lombok, which are about fifteen miles in width at their narrowest part. Despite the narrowness of this channel-which, however, bears evidence of its