The investigation here described may be regarded as the natural sequel of the observations by which I showed that the plaice of the Brown Ridges, as well as those from the Plymouth grounds, were smaller when they attained to sexual maturity than those of the northern part of the North Sea. Mr. Holt, in 1894, published in this Journal some observations on the dwarfed and ciliated or spinulated plaice of the Baltic; and Dr. Heincke, now Director of the German Biological Station at Heligoland, had suggested as a probability that the plaice of the Heligoland region were a smaller geographical race, distinguishable by special characters from those of other regions. I referred to this subject at the end of my paper on the Physical and Biological Conditions in the North Sea, in the preceding number of this Journal, and mentioned the paper in which Georg Duncker has recorded and discussed the results of an examination of samples of plaice and flounder from various localities.

The Journal of our Association cannot be allowed to appear without a few words in memory of our first President, the great naturalist and leader of Science, whom we all mourn.

Huxley's studies in marine biology, and his position as a Government official, as well as his keen, practical common-sense, made his selection as a member of two Government Commissions on Fisheries (in 1863 and again in 1883) very appropriate. He did valuable work on those Commissions, and in 1881 was appointed, by Sir William Harcourt, to be Inspector of Salmon Fisheries. In 1883 he took an active part in the work of the International Fisheries Exhibition, and emphasized in an address given there, the fact that, whilst civilized man had brought all the resources of science to bear on the “harvest of the land,” little or nothing had been done in the same spirit for the “harvest of the sea.”

Corystes cassivelaunus is a crab of unusually narrow and elongated form, which has received the popular name of “masked crab” from the grotesque resemblance which its sculptured carapace bears to a human face. It is common round all the coasts of the British Isles, and, although normally an inhabitant of the deeper water, is occasionally found at home in sandy pools on the sea shore, and is frequently cast up in hundreds on sandy shores after heavy gales.

In the Museum of the Royal College of Surgeons, in London, there are two specimens of the common eel, in which the ovaries are much enlarged, greatly distending the abdomen, and evidently very nearly ripe. Both those specimens were presented by Mr. Geo. Buckeridge, a salesman in Billingsgate Market, who deals largely in eels. The following are certain particulars concerning the specimens:—

(1) Length 15 in., weight 4½ oz. Presented Jan. 4, 1894.

(2) Length 19 in., girth round the abdomen 5½in., weight 10¼ oz. Presented Sept. 25, 1895.

IN my report, in the preceding number of this Journal, on my observations in the North Sea, I referred briefly to the problem of the relation between the physical and biological conditions. This problem will afford scope for investigation for some time to come, and the purpose of the present article is to discuss and compare some of the most recent additions to our knowledge of the matter. The paper by Mr. H. N. Dickson, to which I referred in my previous report, was published in the Geographical Journal last March, under the title of “The Movements of the Surface Waters of the North Sea,” and in the Scottish Geographical Journal, in 1894, was published a series of papers by Professor Pettersson on “Swedish Hydrographic Research in the Baltic and the North Seas.” Professor Heincke has discussed the fish fauna of Heligoland, its composition and sources, in an interesting paper in the series issued under the title of “Wissenschaftliche Meeresuntersuchungen,” by the staff of the Biological Station at Heligoland, in association with the Commission for the Investigation of the German Seas, at Kiel. Professor Heincke's paper is contained in Bnd. I., Hft. 1 of this series (1894), and in the same volume are a number of papers dealing on similar lines with other divisions of the marine fauna of the Heligoland Bight.

It will be most convenient and logical to start the present discussion with a consideration of the results of Professor Pettersson's work. He found that the Skagerack and Cattegat were filled with layers of water distinguished from one another by differences of salinity, and that the lower layers entered the channel as under–currents, and could be recognised at the surface somewhere in the North Sea.

The following pages are intended to be preliminary to a fuller report which I shall hope to publish later on. For the present I shall confine myself to an account of the objects in view of which these investigations were begun, and of the method by which they have so far been carried out. I further propose to append a brief summary of some of the facts ascertained, reserving a more detailed statement for a future occasion.

While engaged in the examination of some vase pictures which have been stated to represent certain parts of the shores of the Bay of Pozzuoli as it existed in Roman times, I was struck by two drawings of Roman Oyster culture grounds, or ostrearia, which seem to me to be of considerable interest, not only as affording us direct information concerning the method of oyster culture employed by the Romans in the neighbourhood of Baiæ, but also because they show clearly that that method was the same as the one which still survives and is still carried on, in common with so many other Roman customs in the same locality, exactly as it was nearly two thousand years ago.

From April 3rd to May 17th of this year I occupied a table at the Plymouth Laboratory, to study the embryology of Teleosteans. As some of the fish in the flat-fish tank were known to be spawning, a net was fitted to the overflow channel into the adjoining tank. By the kind permission of the Director I examined this net daily, and, as a rule, a number of times a day, so that I obtained a pretty complete record of the spawning of the fish in this tank during the period mentioned.

The Effectof The Closureof Inshore Areas Upon The Sizeand Abundanceof The Food - Fishes Which They Contain.—In the Report under consideration Dr. T. Wemyss Fulton, the Scientific Superintendent of the Scottish Fishery Board, publishes an important Review of the Trawling Experiments of the Garland in the Firth of Forth and St. Andrews Bay in the years 1886–1895. As is well known, these areas have been closed to trawlers during the ten years under consideration. The Board's steamboat Garland has from time to time made experimental hauls with a 25 ft. Beam-trawl along certain fixed lines within the areas, the fish captured being measured and recorded, and the results of the experiments published from year to year in the Reports. After ten year's work, Dr. Fulton now gives a general review of the whole investigation, and indicates the conclusions to which, in his opinion, the results of the experiments seem to point.

In the previous number of the Journal, I described my reasons for doubting whether the conclusions drawn by Mr. Holt, concerning the size at which plaice become mature, would hold good for the whole of the North Sea; and also whether the evidence he relied upon, in distinguishing mature and immature plaice, was sufficient. I stated that, as an actual fact, one sample of mature plaice, which were much below the limits of size determined by Mr. Holt, had come into my hands. I suggested, as a probability, that the presence of dead degenerating eggs in the tissue of the ovary was a proof that the fish had spawned, was a spent, and therefore a mature specimen. My words were: “It cannot be asserted as a certainty that these granular masses never occur in an immature ovary; to settle the doubt it will be necessary to make a careful examination of plaice in November and December, when all fish which are about to spawn will have a large amount of yolk in the eggs, and all fish in which the eggs are transparent and yolkless must be immature.” It was already known that these degenerating eggs do occur in spent ovaries, from which the ripe eggs have recently been discharged, and which bear evidence of the fact in their somewhat large size, flaccid and collapsed condition, and usually in the presence of a few detached ripe eggs in their interior.

In accordance with instructions from the Council of the Association, I arrived in Cleethorpes on February 4th last, and proceeded to make investigations into the biological questions presented by the fisheries in the North Sea. A large portion of my time was, however, absorbed by the work of preparing a summary of our knowledge of the natural history of marketable marine fishes, for publication in book form, and consequently the observations to be here recorded are not so extensive nor so complete as I should have otherwise been able to make them. It must also be noted that they are confined to a period of only three months—from the beginning of February to the end of April. The work has consisted only of observations in the fish market at Grimsby Docks, and of the examination of fish there procured in the Cleethorpes Hatchery; I have not been able to make any voyages on fishing boats. I have received from Mr. Holt, my predecessor at this post, all the assistance that information concerning persons and circumstances could afford me, and I have had the valuable services of Mr. Clark, the caretaker of the Hatchery.

A specimen of this somewhat uncommon shark was recently brought to the Laboratory by some fishermen. The following notes on it may be of interest. The fish was taken with a long line baited with mackerel, for conger. It was captured forty miles south of the Mewstone, at a depth of about forty-five fathoms. The specimen was a female, and measured 6 feet 6 inches from the end of the snout to the tip of the tail. The following are the principal other measurements: snout to anterior edge of first dorsal fin, 46 inches; snout to anterior edge of pectoral, 20 inches; the interval between the anterior edge of the pectoral, and the pelvic fin was 26 inches. The first dorsal, which was small, was thus situated immediately above the pelvic. The second dorsal, which was smaller than the first, was situated as nearly as possible midway between the first dorsal and the commencement of the caudal fin. The measurements so far tally with Day's description of the species.

Attention may, however, be drawn to the measurements which follow in connection with the following statement in Day: “Ventral (fin) … commences mid-way between the front gill opening and the end of the caudal fin in elongated forms: or anterior end of the snout and middle of the caudal fin, as observed in the Plymouth and Aberdeen stouter specimens.” (Day's British Fishes, vol. ii. p. 323.)

In my specimen the distance from the front gill opening to the anterior edge of the ventral was 30 inches: thence to the end of the caudal was 33 inches.

At Grimsby there are a number of trawlers—some steamers and some sailing vessels, which are locally called Cleethorpers, and regularly fish on the grounds near the Humber, returning to port at the end of the week. I went out in one of these, the S.S. Rhine, on July 22nd. My object was to examine the grounds near the mouth of the Humber and the Wash, in order to compare them with the grounds off the German coast. We shot the trawl at 2 p.m. the same day, having steamed 55 miles by the log from the Newsand Lightship, at a position a few miles west of the Coal Pit or N.E. Hole, as it is named on the chart illustrating Mr. Holt's description of the Grimsby Trawl Fishery. The depth during the haul was 13 to 18 fathoms. The temperature at the surface was 58° F.

It has for a long time been known that the sea abounds in microscopic organisms, both animal and vegetable. Among the former are entomostraca, infusoria, radiolarians, foraminifera, as well as larvae of mollusca, radiates, and bryozoa. Among the plant-life the mass consists of diatoms, cilioflagellates, flagellates, and certain unicellular chlorophyllaceous algae. For these pelagic forms Prof. Hensen has proposed the name plankton, which has been universally accepted.

The following notes on the collecting work carried out during the period from January to June, 1895, follow the lines of Mr. Garstang's notes for 1892 and 1893. In putting the observations on record, I should like to thank the various workers at the Laboratory during the period covered, for the help which they have given. My own part of the work has consisted chiefly in keeping the record, and in endeavouring to give a certain amount of continuity to the whole. At the same time the final responsibility for the names adopted must be my own.

Many inhabitants of the sea know as well as men do that oysters are good to eat, and the destruction which they suffer on this account can scarcely be less than that brought about by human agency. Starfishes especially extirpate them in great numbers, and Möbius† maintains that they are the most pernicious enemies which the oyster possesses, although, on the other hand, people have not been wanting who held the destruction of oysters by starfishes to be a fable.

The powers conferred on the Board of Trade, under the Sea Fisheries Regulation Act of 1888, to create, upon the application of a County or Borough Council, a local Fisheries District, and to provide for the constitution of a Local Fisheries Committee for the regulation of the sea fisheries carried on within the district, have been requisitioned by the majority of the Councils of the maritime counties of England and Wales, and at the present time Fisheries Districts and Fisheries Committees are constituted around nearly the whole coast line, the Committees having jurisdiction over all fishing carried on within the three-mile limit. The only portion of coast still unprovided for is that which lies in the counties of Norfolk and Suffolk, between Happisburg and Dovercourt.

As my paper in the previous number indicates, my interest in these investigations was chiefly excited by the fact that no satisfactory explanation appeared to have been discovered for the remarkable abundance of small plaice in the German Bight of the North Sea. The explanation suggested, and held by many to be sufficient, was that there was a current from west to east which carried floating or buoyant objects towards the German shores, and that, therefore, the buoyant eggs and larvæ of the plaice were carried thither in great numbers. Dr. Fulton has recently made direct experiments on the course of the drift, by putting floating bottles into the sea in the neighbourhood of the Firth of Forth. In certain cases, out of groups of bottles put overboard at the same spot, some were afterwards found on the English Coast to the south, and others on the coast of Schleswig and the Island of Heligoland. The course thus determined for the general circulation would probably cause more of the plaice spawn, shed in the North Sea, to be conveyed to the German and Danish Coasts than to English. But the difficulty that perplexed me was that the peculiarity of the German grounds seemed to consist not in the greater numbers of plaice generally, but in the exclusive occurrence of small plaice at distances from land at which, on the opposite English Coast, large mature plaice seemed also to occur with the small.

In a communication to the Royal Society (Phil. Trans. vol. clxxxiv. 1894, and in this Journal, vol. ii. no. 1), I described a series of experiments in which light was directed upon the lower sides of flat fishes, by means of a tank with a glass bottom, and a mirror placed beneath it. I have now to record an observation which confirms my previous results in a most striking manner. Curiously enough, the effect I am about to describe, in some respects even more important as evidence than those obtained in my experiments, was observed accidentally, or at least incidentally, and was due to conditions which had been quite unintentionally produced.