CHAPTER XII.

THE FAUNA AND FLORA OF THE CHANNEL ISLANDS CONSIDERED IN REFERENCE TO THEIR PHYSICAL GEOGRAPHY AND GEOLOGY.

It is hoped and believed that the publication of the Natural History lists, in Chapters VIII. and IX., in a state admittedly imperfect, will induce the island naturalists to exert themselves to fill up the lacune. That these are numerous, is a fact of which the collectors themselves are well aware. It is one, however, that requires no excuse. The simple circumstance that

STATE OF THE NATURAL HISTORY LISTS.

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most of the catalogues were made for private use, and were put into the hands of the present writers at a comparatively short notice, anticipates all reasonable objection.*

But if the lists be only imperfect measures of the actual Flora and Fauna of the islands, they are, at least, favourable measures of the extent to which, in their various divisions and subdivisions, they have been illustrated by local skill and energy.

It is not difficult to anticipate the departments in which they will be least unexceptionable and the points upon which the most work still remains to be done. The fullest and the most sufficient lists are those (as we expect, a priori), of the trees, shrubs, and flowering plants, the grasses, the sedges, and the ferns. The nature of the objects themselves is, to a great extent, the cause of this superior accuracy: to greater extent still, the excellent Manual of Professor Babington. The lists of cryptogamic plants generally are the least perfect of the botanical series, and of these the Fungi, perhaps, require most revision. Of the Fauna, we may mention as the most imperfect departments, some tribes of insects, the smaller crustacea, the annelids, and the acalephæ; although many others require careful examination, and a comparison of the species said to occur in the different islands. Perhaps the lists, as a whole, may be regarded as indicating the peculiarities of Guernsey natural history, rather than that of the Channel Islands generally. This arises from the fact that there are more island naturalists there than in Jersey.

That the Fauna and Flora of the islands are those of Normandy and Britany, and that little in the way of novelty is to be expected from even the most microscopic examination, is no reason for neglecting them.

* It will, no doubt, be found that in spite of much care and attention, most conscientiously exercised, many errors of various kinds have crept into the lists. The explanation above given will, perhaps, be admitted as an excuse; and it is hoped that in a future edition the lists will be as much more correct, as they will certainly be fuller.

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VALUE OF INSULAR FAUNAS AND FLORAS.

Even if every list were complete, and if every species contained in each were a French or an English one, with its equivalent on one or both of the opposite coasts, much would remain for the island naturalist that could only be done in the island itself.

Most recent works which go beyond the merest enumeration of species, tell us this; and they do so, by either suggesting or insisting upon the fact, that insular Floras and insular Faunas are invested with an interest of their own, simply because they are insular. In many cases, the smaller the island the more important the phenomena it presents. In its natural productions it either agrees with the nearest point of the nearest continent, or it differs from it; and in either case the fact, whichever it may be, is of interest. Absolute or approximate concordance, like that of the Isle of Wight with Hampshire, is a phenomenon of one kind; extreme difference, like that between Madeira and the coast of Morocco, is a phenomenon of another kind; and in skilful hands, as much may be made of the one as of the other. The intermediate case is that now before us.

During the collection of the preceding lists, the more prominent questions connected with these matters have never been wholly overlooked; these prominent points more especially meaning, to the English reader at least, the speculations of the late Edward Forbes respecting the distribution of plants and animals over the British Islands, and those of Mr. Vernon Wollaston, upon the effects of what may be called insulation (i. e., exposure to the influences of island), in the development of varieties-varieties which, in many cases, are of sufficient extent to engender the appearance of specific differences.

In respect to the first of these questions, it is not only beyond a doubt, but transparently clear, on even a cursory inspection, that the natural history of the islands is French rather than English. It is not only more French than English, but it is decidedly French-French, however, with several notable points of difference. It is the insularity (the islandhood, so to say), of

ABSENCE OF CERTAIN SPECIES.

301 the islands, which determines these. In this respect, as we have already explained in the chapter on Climate, Guernsey is the typical district. Jersey is, in fact, pre-eminently French, and Sark somewhat less intermediate than might be expected. Guernsey, in other words, is the most of an island; Jersey the most of a peninsular portion of the terra firma of France. Amongst butterflies, the grapta C. album has contrived in its excursions from the Continent to reach Jersey, where it is by no means scarce; it has yet, however, to find its way to Guernsey and Sark. It may be, that although originally present in all the islands, the conditions favourable for its preservation have been removed by the more perfect insulation that has been produced in the more distant islands in course of time, causing the species to die out. Whatever the reason may be, however, the absence of this species amongst others marks a significant fact. It is from the due consideration of such facts in sufficient number and variety that generalisations are made, and the physical geography and ancient history of physical change of the islands explained and illustrated.

Compared with many other isolated tracts of equal extent, the Channel Islands are rich in both species and individuals; and they are this, so far as they are continental as well as insular. Compared with many other isolated districts, they are characterized by the continental character of their species; or rather, they are conspicuously characterized by the absence of anything peculiar and special to themselves. So far as they are this, they are also continental,-continental of the continent of France.

Concerning the doctrine that the bulk or size of individual animals is encouraged by the conditions which a continent, and discouraged by those which an island presents, a doctrine (or rather complex of doctrines) more especially connected with the researches of Mr. Wollaston-what say the Channel Islands? Mr. Wollaston, considering the diminution in the size of beetles

in detached islands, refers it to the constant and repeated breeding from the same stock. That the bulk of the facts which he has with great care and much discursive investigation brought to bear on his doctrine are realities, is as transparently true as it is true that the doctrine itself is an hypothesis. The question whether certain animals in small islands lose size from the simple fact of breeding in-and-in is one thing, and the question whether they lose size at all, irrespective of the reason why, is another. The latter is the primary one. Every fact, however, commands its due amount of attention; and if there were only one insect in one island which, on the strength of its being an insular representative of a continental species, had been subservient to either the verification or the confirmation of a legitimate hypothesis, no observer would be justified in ignoring the line of enquiry which it suggested. He need not be a naturalist, ex professo, to do it. He need only be able to keep his eyes open for certain facts, and when any one of the kind required came within his ken, to make a note of it. There is no need for any writer who (happening to know that the entomology of Lundy Island, the Flat Holmes, and the Scilly Isles, have been studied with a view to certain phenomena) is also writing about the Channel Islands, to excuse himself for lookingout for such relevant facts as he can appreciate, and for laying them before the reader as he finds them.

The model way of working some of the problems suggested by the statement that the bulk of individuals falls off in insular localities, would be to take (say) a hundred weight of continental and a hundred weight of insular beetles, or butterflies, and get the difference (if there were one) in gross. But this is what ought to be rather than what is. Nor if it were otherwise, could certain preliminary cautions be dispensed with. It is the opinion of a good and competent observer that butterflies and moths reared in the ordinary way, from the caterpillar state in confinement, are, as a rule, smaller than those caught. Now in the