these fish is well known. They are contained in a grey compact limestone from one of the lower hills which abut on the Alpine range between Verona and Vicenza. They belong to that mysterious but most fruitful Miocene or later Eocene age when the vegetation of a warm climate covered some great continent which extended to near the Pole, and the remains of whose luxuriant forests are now sealed in the rocks, and under the Glaciers of Greenland and Spitzbergen. How that vegetation could flourish under the conditions of darkness which must have always prevailed during winter in the Arctic regions, is a problem not easily solved. In the land which is now Italy the vegetation of that time seems to have been tropical or sub-tropical. Large leaves and stems belonging to various species of Palm were abundant on the marble slabs which also contained the fish. The great interest of that age lies especially in this-that there is reason to believe that during it there was continuous land between at least the northern parts of Old and the New World, and that the community of animal forms which still marks the fauna of the two great Continents of the Globe dates from that epoch.

On the floor of the grand old Lombard Church which is dedicated to San Xeno, the Patron Saint of Verona, I saw what explained in some degree the history and structure of that very peculiar local marble which has been so extensively used in all the ecclesiastical buildings and decorations of the North of Italy. It is a marble of different tints of a dull red and of reddish yellow passing into each other in a mottled pattern not unlike the dapplings on the coat of a horse. On one of the steps of this marble leading down to the beautiful crypt there is a very fine specimen of an Ammonite, and on other portions of the pavement, which is all composed of the same material, I detected several other less perfect examples, some of which seemed to me to reveal the fact that this marble is almost entirely composed of the septa or joints of these old Cephalopods or Cuttle-fish which have been broken up and re-cemented in one common calcareous paste. The place occupied in the history of organic life by the several orders of Cuttle-fish which lived in chambered shells (Nautilida) is extremely curious. In the most ancient rocks in which they appear these shells were quite straight, cylindrical, and tapering to a point—hence called Orthoceratites. In later ages they became curled inwards towards the point. Still later this curling increased, until the shell became convoluted, or twisted round a centre. Still later, again, these convolutions became closer, and, as it were, tighter, until at last they assumed the well-known coiled form of the Ammonite which, of various patterns, flourished in innumerable quantity in the Seas of the Secondary Age. They are still represented in our existing seas by one or two species of Nautilus, which, although a very beautiful shell, is but a fragile representation of the splendid and massive forms which have been fossilized in the Oolite and the Lias. The great interest attaching to this vast variety of forms in the science of

Biology lies in the fact that, in respect to them, or, at least in respect to one great serics of them, it cannot be argued that the Geological record is imperfect. That record is, indeed, always very imperfect in respect to terrestrial forms of life, because comparatively so few of them can ever be preserved in aqueous deposits, and because so many get destroyed. But the same conditions do not attach to those forms of life which have been marine. A complete and perfect series of certain of these forms may very easily be preserved in the deposits of any given age. The imperishable nature of shells generally, and especially of shells so solid as the Ammonites, together with the fact that all that lived in any given area of sea must have been preserved in its deposits, as we actually find them to have been-are circumstances which give us every reason to believe that we have a very complete record of the succession of these forms, and this, too, for periods of time so long that during them many new species did actually appear. In the deposits of the Lias, for example, we have in the South of England, and elsewhere, an immense series of deposits which appear to have been continuous and undisturbed during the time of their deposition, and are continuous and undisturbed still. They are crowded with millions of Ammonites of all forms and patterns, of all ages and sizes, and yet the method or the process by which new species have been introduced is as mysterious in respect to them as in respect to other forms of life in which no such perfect series anywhere exists. No less than two hundred species are known in this one geological formation, of which one hundred and six are confined to a particular division of it. All these appeared quite suddenly, and in the next division of the same deposit their places were taken by forms which are wholly new.* Whence did these come, and how did they arise? No man can tell. The facts do not suggest gradual passages and insensible gradations. One particular species, for example, appears suddenly in one particular bed or stratum only a few inches thick -appears in this bed alone, and is absolutely wanting in every other whether above or below it. True it is that the differences of pattern which distinguish these species from each other are often small. But whether they be large or small they are always constant. They appear suddenly, and as suddenly their place is supplied by some new variety which during another period remains as fixed and constant as all the rest. It seems to me to be quite certain, from this history of the Genesis of Ammonites, that the origin of their specific distinctions has not been an origin due to minute and accidental variations, but an origin due to sudden changes effected under a law of birth or of evolution of which we know nothing, and to which nothing analogous has been ever seen since Man appeared, or at least since Man observed. The doctrine that Nature does nothing" per saltum " is a doctrine which, in so far as it is true at all, has been wonderfully misunderstood. The continuity of Nature is

I owe these details to my friend Mr. Etheridge, of the Geological Survey, who is the highest authority on the subject.

a continuity of causation, not a mere continuity of effects. New things may appear very suddenly in perfect consistency with being the result of long and gradual preparation. Leaps the most tremendous -transitions the most violent-may be the outcome of a perfect continuity. If all creatures have been born from pre-existing forms, the Geological evidence is that they have been born suddenly-with deviations from the parent stock, which have been reached at once-and which have remained fixed and definite until a new variation has arisen.

On our breakfast table at Venice I made a discovery in natural history which surprised me much. Among some slices of fried fish there were certain pieces of a peculiar shape, which on being tasted betrayed themselves at once as crustacean, and crustaceans, too, of peculiar excellence. They seemed like gigantic Prawns taken out of the shell and fried. An immediate investigation followed. The waiter could give me no satisfactory information. The landlord, on being appealed to, could only tell me that the dish was composed of a kind of Lobster or Crayfish which was much esteemed at Venice. I begged that some specimens might be brought to me in the shell. What was my astonishment to see produced my old friend the Norway lobster (Nephrops Novregicus), a crustacean of the northern seas, and yet here apparently abundant in the Adriatic. The circumstances connected with this beautiful crustacean are peculiar. Although I have recently found it to be abundant on the west coast of Scotland, I had never seen this Lobster, or even heard of it, until I began some eight or ten years ago to use a dredge net from a steam yacht at depths and in places not usually resorted to for taking fish. Its habitat on the west coast is at depths from ten to twenty fathoms on a muddy bottom. It is rare,

or wholly absent, in the deep arms of the ocean which form the sealochs of the Western Highlands. But I have dredged it in abundance round the shores of Mull, of Eigg, and of Arran. When fresh caught it is one of the most beautiful creatures which can be taken out of the sea. Instead of the dark browns and blues which are the colouring of the Lobsters and Crabs that frequent shallower water, and which have long been known as articles of food, the Nephrops comes out of the water shining in brilliant and transparent tints of yellow, of orange, and of red-with a carapace or shell of exquisite sculpturing -long graceful legs and claws, ornamented with embossed balls and ridges of the purest white; large black eyes, and antennæ as if made of coral. Of late, dredging operations for flat fish have been extending on the coasts of Scotland, and I was glad to see last autumn a good supply of the Nephrops on sale at the shop of Mr. Anderson, the fishmonger, in George Street, Edinburgh. They were reported, however, to be considered comparatively tasteless and very inferior to the common Lobster. But I must stand up for the Nephrops, the flesh of which is, in my opinion, always good, and, when cooked as it was cooked at Venice, is really excellent. But now for the

In

curiosity of the occurrence of this crustacean at Venice ;-so far as my opportunities of observation have gone, it is unknown on the Riviera coasts of the Mediterranean. A large spiny Crayfish, quite as large as an average Lobster, is common in the markets of Cannes and of Genoa. Smaller crustaceans of peculiar and interesting forms are not uncommon. But nothing like the Nephrops is ever to be scen. never seen it in the London markets, nor in the local markets of the south of England. It seems to be essentially a northern form. How is it that it reappears in the Adriatic? This opens a very curious question on the distribution of marine life, and on the geological history of the corresponding distribution of land and sea. Is it possible that the Adriatic may be a portion of the Mediterranean basin which at one time had a communication with the northern seas, and that the Nephrops is a survivor of a northern fauna which has been destroyed in the warmer waters of the rest of that basin? If this be so, the Nephrops will not stand alone; but the fishes of the Adriatic, and probably other marine forms, will show the same old connection. It was in harmony with this inference that I observed Soles and Flounders in the markets of Venice, which seemed to be also of a northern type, and very different from the fishes of the rest of the Mediterranean. like manner some shellfish (bivalve mollusca), which I saw being eaten by the gondoliers in Venice, seemed not less distinctly like the forms with which I am familiar on the coasts of Scotland. The large quantity of snow water which descends into the Adriatic from the Dinaric or Dalmatian Alps, and from other high mountain ranges which discharge their drainage into it, keeps down its temperature below that of the rest of the Mediterranean, and, as a consequence, I learn from Dr. Günther that it is the only portion of that sea which contains Salmonida -true migratory Trout which ascend the rivers and descend again into the salt water. Such is also the case, I believe, with the Black Sea, into which the great Salmo hucho ascends and descends along the Danube. This, however, is a much less significant fact than the existence of a peculiar northern fauna, purely marine, in the Adriatic, because there are Trout in abundance in streams which fall into the Gulf of Genoa ; and, although they are not migratory in the streams of the Maritime Alps, and never descend into the Mediterranean, yet the habit of migration into the sea might be acquired and again lost according to changes of temperature. But a purely marine form which belongs to a northern fauna cannot have been introduced into the Adriatic except by some geographical channels of communication with the Atlantic. It is just possible, but not probable, that the Nephrops may really exist continuously in the deeper waters of the Atlantic and of the Mediterranean all the way from the Irish and Scotch shores to the Adriatic, and may approach the shoaler waters there only because of their lower temperature. My own belief, however, is that the peculiar fauna of the Adriatic is the survival of a time when the waters of the North Sea found

entrance there over what are now the lower passes of the Alps: and that this time belongs to that period of the Glacial epoch when we know from other evidence that there was a submergence of the land in our own Islands to the extent of at least two thousand feet. Mr. Gladstone has inferred from the Homeric poems that in their time the Adriatic was conceived to have an outlet to the North. I am afraid, however, that it would be safer to attribute this notion to the imagination, or to the limited knowledge of the Bard, than to suppose that in an age which, after all, is comparatively recent, there can have been any living memory or tradition of a condition of things dating from the Great Ice Age.

There is, indeed, another question of far higher interest connected with this great submergence or subsidence of the Land towards the close of the Glacial epoch. Some recent papers by M. Lenormant on the various traditions of the world on the subject of a Deluge, have summed up the evidence in favour of the universality of this tradition, and of the conclusion that it points to the memory of some actual fact, and not merely to a common fancy or imagination. Now, one thing seems to be certain-that no sudden or even rapid submergence of the land beneath the sea could have taken place in times so recent as the first existence of Man, without leaving evidence of the movement in the distribution of gravels and other transported material over the whole area submerged. The question therefore arises-have we any such evidence? The childish attempts which were made in the beginnings of geological science to connect the discovery of fossil shells with the traditions of a Deluge, have thrown such discredit upon the very idea of there being any geological evidence whatever in favour of that tradition, that the question has almost ceased to attract attention. Yet I cannot help thinking that recent discoveries must inevitably revive it, although in a form which is entirely new. The Deluge, if it ever happened, must have covered immense areas of country with sand and gravel. Subsequent denudation by rain, by rivers, and by the currents produced during the process of re-elevation, would certainly obscure that evidence, and we must therefore expect to find it broken and fragmentary. making allowance for this, it seems to me that such evidence does exist in the existing distribution of sands and gravels, which are known in geology as the quaternary gravels-and in the fact only ascertained in recent years, that these gravels do contain, in some places abundantly, the proofs of the pre-existence of Man. It is, indeed, usually assumed that all these gravels are river-gravels, that is to say, gravels always deposited by existing streams, and not by marine action.

But

Even if this were true it would by no means dispose of the question, because there are conceivable conditions under which the materials transported by a Deluge might, in particular places, be of purely local origin. But the evidence in favour of this limitation seems to me to be inconclusive. My impression is that the flint weapons of the so-called Palæolithic