The present number of the Journal contains several memoirs of considerable practical importance. Mr. Bateson's paper on The Sense-organs of Fishes is the outcome of six months' work at Plymouth. It will be seen that he has dealt with the subject in the broadest possible manner; and whilst he is able to offer many practical suggestions as to the course to be pursued in further experiments with preserved and artificial baits, he has prepared the way for such experiments by his careful and interesting observations on the manner in which various fishes hunt for their prey. These observations give a far more accurate and well-founded account of the habits of food-fishes than anything that has been published before.

The following is a detailed account of the results of my investigations concerning the breeding and the development, under natural and artificial conditions, of some of the fishes met with at Plymouth. These researches extended over the period from the beginning of August, 1887, to the end of August, 1888. I have given brief preliminary accounts of some of the results in No. II of the ‘Journal,’ issued in August, 1888. As I mentioned there, the laboratory work was carried on from August to November in a small room hired for the purpose near the fish quay; from November to June, 1888, in a single room in the Laboratory without a constant supply of sea-water; after that time the Laboratory being finished all its appliances were available.

The Council of the Marine Biological Association appointed me, in 1889, to make observations on the perceptions of fishes, and especially on those which constitute the modes by which they hunt for and recognise their food. It was suggested that this subject should be treated in as wide a manner as possible, and in accordance with this suggestion I have endeavoured to utilize any opportunities which presented themselves of getting an insight into the natural history of marine animals. In addition to this I have also made some experiments towards the practical solution of the bait question, both by making artificial baits, and by endeavouring to preserve materials which are already in use for bait.

While on a visit to Holland last December, I took advantage of the opportunity to learn something of the extent and methods of oyster culture there practised. To Mr. C. J. Bottemanne, of Bergen-op-Zoom, the Inspector of Fisheries, and to Prof. A. A. W. Hubrecht, of Utrecht and his published papers, I desire to acknowledge my indebtedness.

The following is a list of the Invertebrates which I had an opportunity of examining. Their pigments were not in all cases thoroughly studied, partly because the Laboratory had been opened but a short time before my arrival, and was not yet fully provided with the necessary chemical apparatus, partly through want of time.

The anatomy of Dinophilus, a genus established by Oscar Schmidt in 1848, has formed the subject of several memoirs, amongst which attention must be specially called to the recent papers of Korschelt (6), Repiachoff (12), and Weldon (13). A complete account of the synonymy of the genus was given by v. Graff in 1882, whilst Korschelt (7) has, within the last year or two, published a review of the facts known with regard to the anatomy of the various species of Dinophilus.

Before 1888 no specimen of Tornaria, the well-known pelagic larva of Balanoglossus, had been taken off the English Coast. But on August 9th of the past year Mr. Weldon, using the surface net near the Eddystone Lighthouse, took several young specimens of Tornaria, and subsequently the same gentleman, during a cruise of a week's duration towards the end of August, captured many larger and more mature specimens of the same larva. Other specimens were taken by us up to September 21st, and in the month of August, Mr. Rupert Vallentin found several specimens in the vicinity of Falmouth.

The specimens taken on these occasions form the subject of the present memoir, and their anatomy is detailed at some length, both because of the interest attached to a form bitherto unknown to England, and because it is in some respects of morphological importance.

The specimens taken by us came from the offing, and were not taken within four miles of theshore; Mr. Vallentin's Tornaria were found close to the shore at Falmouth. As he was able to bring his back alive and preserve them at leisure in his laboratory, they are better preserved than those taken by us, since we were obliged to preserve our catch in a somewhatrough manner out at sea. An examination of Mr. Vallentin's specimens leaves me no doubt that the larva is Tornaria Kröohnii, aspecies found in the Mediterranean. The different forms of Tornariahave not been with certainty referred to their adult forms, but T. Kröohnii must belong to one of the Mediterranean species of Balanoglossus, that is to say, to B. Kowalevsltii, B. minutus, or B. claviger, species which have not hitherto been recorded from the English Channel, unless we suppose that the larva of B. salmoneus v. sarniensis, which occurs in the Channel Islands andat Roscoff, is identical with Tornaria Kröohnii.

The following description of the reproductive organs of the oyster cannot well be understood without some acquaintance with the general anatomy of the animal. With the help of Pl. XXII, fig. 1, the most important features of its anatomy may readily be understood. It must be remembered that the valves of the oyster's shell lie right and left of the animal; that the concave valve which lies undermost in the natural position of the animal is the left valve, and the flat upper valve is the right valve. The hinge marks the dorsal border of the animal, and the opposite border is the ventral border. That side which is on the observer's right in fig. 1 is the anterior surface, and that on the left hand is the posterior surface. As the animal is compressed from side to side the anterior and posterior surfaces are very narrow. The great adductor muscle, by which the valves of the shell are closed, is seen lying in the centre of the animal in fig. 1.

Mr. Wilfrid Grenfell, the Superintendent of the Mission to Deep Sea Fishermen, has most kindly arranged to carry on a series of observations on the pelagic fauna and the fishes of the seas traversed by the Mission boats in the course of their work. The following report gives an account of the pelagic fauna collected in the North Sea during the early spring, and in the west of Scotland and Kinsale Harbour during the summer. The collections were preserved in picro-sulphuric acid and spirit, and were forwarded to Plymouth for examination. Owing to pressure of work, and to my leaving Plymouth somewhat unexpectedly, I have not been able to make a thorough investigation of all the collections, but have worked out the Copepoda with care, and have confined myself to short notes on the other species.

The Oligochæta form a division of the Annelida, of which the most familiar type is the common earthworm (Lumbricus terrestris); the group comprises also a great number of smaller worms, which are for the most part inhabitants of ponds and streams, such as the red River worm (Tubifex rivulorum). The Oligochæta were at one time believed to be entirely terrestrial or inhabitants of fresh water, and to be distinguished thus from the Polychæta, which were supposed to be exclusively marine in their habitat. Although the progress of research has not broken down the structural distinctions between these two divisions of the Annelida chætopoda, it has been provedthat no absolute line of demarcation can be drawn between the Oligochæta and the Polychæta as regards their habitat; on the one hand Polychæta have been found in fresh water, and, on the other hand, certain species of Oligochæta are now known to inhabit the mud and gravel of the seashore.

The Copepoda not only form the greatest part of the pelagic life in temperate seas, but are also of the greatest importance in pelagic economy. Feeding on minute organisms and particles of animal and vegetable matter, they are themselves a prey to larger organisms. Some fishes such as the herring, pilchard, and mackerel feed almost exclusively on Copepoda at certain seasons of the year, and experienced fishermen are accustomed to look on the swarms of Copepods which make their appearance in the spring and early summer as the sure precursors of a shoal of fish.

I have tried breeding oysters in two enclosed ponds for over ten years. I began my experiments in 1878. These ponds are situated on the banks of the Beaulieu River, about three miles from the estuary. They were excavated from the mud-bank, and banked off from the river; the bottom was well chalked, and afterwards well coated with gravel. They are about half an acre each, and are divided by an embankment. There are three sluices communicating with the river from the ponds, and two between the two ponds. The situation of the ponds is very sheltered, being in the west bank of the river, with a wood on the west side, and the woods on the east side of the river also sheltering them. The water of the river at the spot is brackish to a certain extent, and decidedly so when there is much rain. At spring tides it is nearly as salt as the sea, but there is always a considerable mixture of fresh in the river. I have only once succeeded in obtaining any large fall of spat, and that was in the first year the ponds were made, 1878. That year there was a very early fall of spat, middle of June, and the tiles were fairly smothered with it. Since then there has been occasionally a little fall of spat, but nothing at all satisfactory.