bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations on Patella Vulgata. Part I. Sex-Phenomena, Breeding and Shell-Growth
Authors: Orton J. H.
Published: May 2009

The small individuals were examined before the height of the breeding season, and there is a probability that many or most of the indeterminate individuals would become male. Hermaphrodite individuals have been observed previously, and in certain samples 10% of the males contain
doubtful young ova in the gonad. It is therefore concluded that Patella vulgata is apparently a protandric hermaphrodite, but that the evidence is not yet sufficiently good to prove protandry.

It is suggested that possibly two kinds of male, which may be recognisable by chromosome constitution, may occur, one being pure male and one protandric, and also that sex-change may be controlled by as yet unknown metabolic conditions.

The breeding period is discussed ; it may extend from August to March at Plymouth in different seasons, and spawning may occur within this period. A maximum of spawning appears to occur about January-February. The conditions controlling breeding and spawning in Patella are unknown, and as the course of seasonal shell-growth is unknown, although shell-growth is general at the end of the breeding season, it is suggested that research on the subjects in the future should be combined.
The Larval Stages of Balcis alba and B. devians
Authors: Lebour Marie V.
Published: May 2009

The young stages of the members of the family Eulimidæ are little known, the only reference to any species apparently being that of Loven (1844) who briefly notes and figures a veliger which he attributes to Eulima distorta (=Balcis devians). This has a very oblique shell and was probably a week or two old. A comparison of this figure with the apex of Balcis devians from Plymouth and its larvæ in the plankton makes one rather uncertain of its identity but shows that even in those early times it was known that a Eulima could remain some time in the plankton as a veliger.
On the Occurrence of Post-Larval Stages of the Bass, Morone labrax (L.), in the Plymouth Area
Authors: Russell F. S.
Published: May 2009

The post-larval stages of the bass, Morone labrax (L.), have never been recorded from these waters. From time to time occasional specimens of young fish have been caught in the plankton which had been tentatively assigned to this species on account of their similarity to the drawing given by Raffaele (1888). Now that the post-larval stages of this species have been described and figured by Bertolini (1933, p. 310 and Plate XIX) the Plymouth specimens can be definitely identified as Morone labrax, and the instances of their occurrence put on record.
A Comparison of the Biology of Echinus esculentus in Different Habitats. Part II
Authors: Moore Hilary B.
Published: May 2009

1. Echinus esculentus was studied from four localities in the Isle of Man and from one in the Clyde.

2. The inshore races are thicker shelled and natter, and on all grounds the urchins become taller with increasing age.

3. Size distribution measurements on the Chickens material showed a rapid growing period in the spring, followed by cessation of growth for the rest of the year. There is a correlation between amount of growth in a given year, and the sea temperature. On the Breakwater the males and females grow at slightly different times of year.

4. Concentric pigmented rings are demonstrated in the test, and are shown to be annual. They are used for estimating the growth rates on the different grounds, which are compared.

5. The duration of life is four to eight years, and perhaps more in the very large southern urchins.
A contribution to the biology ofIanthina janthina(L.)
Authors: Wilson Douglas P. , Wilson M. Alison
Published: May 2009

The summer of 1954 will long be remembered for lack of sunshine, excess rain and frequent high winds over England and Wales. In the south-west of the region the winds from June onwards until the end of the year were predominantly westerly, often reaching gale force, and the total run of the winds was often above average. During the last week of July there were persistent westerly winds from well out in the Atlantic, often strong and reaching gale force at times, particularly on the 27th and 28th. During the last 4 days the winds were generally from the north-west at Scilly and in southern Ireland. They were variable in strength and direction early during the first week in August, but occasionally blew freshly from the south-west. On the 7th it was often blowing strongly from the west, a gust of 50 knots being recorded at Scilly. It was during this first week in August that the first few specimens ofIanthina janthina(Linnaeus) came ashore, heralding the most extensive strandings of this species on British shores for very many years.
Notes on the biology of Sertularia argentea L.
Authors: Hancock D. A. , Drinnan R. E. , Harris W. N.
Published: May 2009

A fishery has developed in recent years in this country for certain hydroids collectively termed ‘white weed’. The hydroids, particularly Sertularia and, more recently, Hydrallmania, are raked up from the sea-bed, processed, dyed and used, largely in the United States of America, for decorative purposes. Fishing for white weed is not new, for it was practised in Germany between the wars. German scientists, notably von Reitzenstein (1913), Pax (1928), and Thiel (1938), examined various aspects of the fishery, and of biology of the hydroids concerned.
On assessing the age of deep oceanic water by carbon-14
Authors: Cooper L. H. N.
Published: May 2009

The rate of circulation and age of the deep water of the oceans is of much interest. Worthington (1955) has suggested an age of 100–160 years for northern North Atlantic water which has reached the Carribean and Cayman Seas. I (in part. Cooper, 1955, 1956) have suspected that the rate of circulation of much of the North Atlantic deep water may be even faster than Worthington's results suggest. Provisional direct observations by G. Wüst & G. Dietrich (private communication) also suggest that the deep circulation is quite rapid.
The growth rate of Chthamalus stellatus (Poli)
Authors: Barnes H.
Published: May 2009

Detailed data have recently been given on the growth rate, under varying conditions, of the common barnacles, Balanus balanoides (L.), B. crenatus Brug. and B. balanus (L.) da Costa (Barnes & Powell, 1953; Barnes, 1955; Barnes & Barnes, 1954). This work has now been extended to Chthamalus stellatus (Poli). Some observations have been made on populations growing in their natural habitat, but most relate to animals growing under conditions of continuous immersion such as are obtained by exposure from a raft.
On the scyphomedusae Nausithoë atlantica Broch and Nausithoë globifera Broch
Authors: Russell F. S.
Published: May 2009

Broch (1913) described two new species of the coronate scyphomedusa Nausithoë from the North Atlantic, N. atlantica and N. globifera. Bigelow (1928, p. 498) was inclined to think that these two species might finally prove to represent extreme variants of the one species N. rubra Vanhöffen, though a much larger series of specimens in a better state of preservation would be needed to give a definite decision. Kramp (1947, p. 46) considered that N. globifera at any rate was a good species.
Observations on the shoaling behaviour of cod (Gadus callarias) in deep water relative to daylight
Authors: Ellis G. H.
Published: May 2009

It is well known that vision is the main physical factor governing the formation and maintenance offish shoals, and that, in general, shoals break up when the light intensity falls below a certain level. Breder (1929, 1942), Newman (1876), Parr (1927, 1931), and others, have shown this by laboratory experiment.

During a commercial fishing voyage to the Barents Sea it became possible, by means of a recording echo-sounder, to study the shoaling behaviour of cod in deep water relative to light intensity. The observations were made aboard the Hull trawlerLancellawhilst fishing in a depth of 110 fathoms at Skolpen Bank in September 1955. For this a Kelvin and Hughes recording echosounder type MS. 24J was used, the depth range across the chart being 55 fathoms. The scale was phased so that the region between 80 and 135 fathoms deep was displayed.
Note onCapulus ungaricus(L.)
Authors: Sharman Margaret
Published: May 2009

The marine gastropodCapulus ungaricus(L.) is found on rocks and shells, and is known often to associate with filter-feeding lamellibranchs, particularly frequenting beds ofPecten maximus(L.),Chlamys opercularis(L.) andModiolus modiolus(L.). It has also been found on the shells of livingTurritella communisRisso (Jones, 1950, unpublished) and on the superior part of the calcareous tubes ofProtula intestinumLam. (Lo Bianco, 1888).
Two new marine species of Gymnodinium isolated from the Plymouth area
Authors: Ballantine Dorothy
Published: May 2009

The two new species, Gymnodinium vitiligo and G. veneficum, which are described below, are both small and highly motile, and in other respects very similar. The greatest difference between them is physiological, as G. vitiligo is harmless, whereas G. veneficum produces a very powerful toxin which is lethal to fish. There are also small morphological differences which are visible when the organisms are in culture, confirming the existence of two separate species.
The Nansen closing method with vertical plankton nets
Authors: Currie R. I. , Foxton P.
Published: May 2009

Several methods have been devised for sampling plankton in the different water layers in the ocean, but for many years vertically hauled nets closed by a method devised by Nansen (1915) have fulfilled this purpose. Recently, however, an investigation by Barnes (1949) cast doubt on the validity of this method for quantitative work, and as in his paper he specifically referred to nets of the type used on the ‘Discovery’ Expeditions, the present observations were conducted to determine whether Barnes's findings were of general application to the method.
Studies on the endocrinology of isopod crustaceans. Moulting inLigia oceanica(L.)
Authors: Carlisle D. B.
Published: May 2009

Experiments performed upon decapod crustaceans have produced much information on the hormonal control of moulting in this group. So far as I am aware, however, no one has tried to discover how moulting in other groups of Crustacea is controlled. This note represents the beginning of an attempt to investigate this aspect of moulting in the Isopoda.
Report on the Present State of Knowledge with regard to the Habits and Migrations of the Mackerel (Scomber scomber).
Authors: Allen E. J.
Published: May 2009

The mackerel (Scomber scomber) is a pelagic and migratory fish, which during the warmer months of the year frequents the coastal waters in the northern temperate region of the Atlantic. The whole form of the fish is evidently well fitted for swift motion and the free-swimming mode of life. The spindle-shaped outline of the body, its perfect curves and rounded surfaces, the absence of all irregular projections which would tend to retard forward movement, the great muscular development of the tail, and the deep forking of the caudal fin, combine to produce an almost ideal adaptation for propulsion at high speed through the water.
Note on New or Rare British Marine Polyzoa.
Authors: Harmer S. F.
Published: May 2009

This species was originally found by Ehlers at Spiekeroog, an island off the coast of E. Friesland, in the North Sea. It has more recently been found by Joyeux-Laffuie at Luc-sur-Mer (Normandy), and by Prouho at Roscoff and at Banyuls. Its wide distribution, from the North Sea to the Mediterranean, made it almost certain that it would be found in British waters when looked for in the right place. Ehlers discovered it in the substance of the tubes of Terebella (Lanice) conchilega, while Joyeux-Laffuie and Prouho found it in the tubes of Chætopterus.
On Tubularia crocea in Plymouth Sound
Authors: Browne Edward T.
Published: May 2009

During my visit to the Plymouth Laboratory in September, 1895, Mr. Roach brought in, on the 28th, some fine colonies of Tubularia which he had found attached to the stern of a large three-masted sailing ship, the Ballachulish, of Ardrossan. This ship had come direct from Iquique, Peru, and after staying a few days in the Sound left for London. The Tubularia was kindly given to me for identification by Mr. E. J. Allen. After making drawings and noting the variation of the different organs, I came finally to the conclusion that as it agreed so closely with Parypha crocea, Agassiz, from Boston Harbour, there was no need to add another species to the genus. I was fortunate to meet with colonies of both sexes, and to find the ova in various stages of development. I believe enough material has been preserved to trace the development of the ovum, which shows a remarkable similarity to the development of the ova from the medusa of Hybocodon prolifer.

Actinulæ were being liberated in large quantities when the colonies were taken from the ship, so it is possible that this hydroid may become an interesting addition to the fauna of Plymouth Sound.

To distinguish this species it is necessary to examine the female gonophores, and count the number of apical ridges. Agassiz states that the number varies between six and ten, but only eight were present in my specimens. The male gonophore is destitute of ridges, and usually terminates in a blunt apex.
Hjort's Hydrographic-Biological Studies of the Norwegian Fisheries: a Review.
Authors: Garstang Walter
Published: May 2009

Scandinavia has been for a number of years past the centre of interest in hydrographic inquiries. The waters of the Baltic, Skagerack, and Cattegat, have been thoroughly investigated by Swedish men of science; the complicated currents of those seas and their periodic alterations have been determined and explained; and a relation has been found to exist between the movements of herring and mackerel and the periodic changes in the character of the water which bathes the Swedish shores. The brilliant results attained by the Swedish hydrographers have been fully described by Prof. Otto Pettersson in the tenth volume of the Scottish Geographical Magazine (1894), and a critical summary of these results is included in Cunningham's paper on the “Physical and Biological Conditions of the North Sea,” published in this journal last year. (Vol. iv., 1896, p. 233.)
An Account of the Scientific Work of the Northumberland Sea Fisheries Committee.
Authors: Meek Alexander
Published: May 2009

Just as a small marine laboratory is being fitted up at Cullercoats, it may be desirable to present to a wider audience a short account of the scientific work already done—work which has, in fact, given origin to the building now almost ready for occupation. As regards the laboratory, a word may be said. It is small, but it will be provided with a tank-room and the essential requirements for carrying on, at any rate, biological investigations. The tanks are made of wood, and will be supplied by gravitation in succession. At the same time a series of glass cylinders can be added in any number, and supplied with sea water in a similar manner. The workroom is very cheery, well lighted and well ventilated, and will accommodate six or even more workers. We are indebted for this most desirable adjunct to the biological department of the College to the Vice-Chairman of the Committee, who has already done so much for local fishery questions. The laboratory will, we hope, not only help in the development of our biological work, but form a centre for enquiry, and thus take a share in the general work of investigation now going on in this country.
Gadus Esmarkii, Nilsson, the Norway Pout, an addition to the Fish Fauna of the English South-Western District.
Authors: Dunn Matthias , Holt Ernest W. L.
Published: May 2009

In the summer months, for some years prior to 1887, very large quantities ofHake (Merluccius vulgaris) had been caught by trawlers beyond the entrance of the Bristol Channel, and landed at Plymouth. Knowing that such masses of hungry creatures would not be found continuously in any given locality without a heavy balance of smaller fish being in their neighbourhood as food for these hakes, I became anxious to know what these smaller fish were, and throughout the summer of 1888 I tried more than once to get at them through our fishermen, but failed.

In July, 1889, I desired my son Howard to visit the Plymouth Barbican, and notice the gutting of the hakes there and tell me the result. His report was that they had been feeding on small whiting (Gadus merlangus), and that single hakes had as many as ten whiting in their stomachs. I told him that I doubted if these small fish were whiting, and asked him to send the specimens at once, as I expected them to be the poutasson(Gadus poutassou) of Couch. I had recently had specimens of this fish brought me from thirty miles west of the Scilly Isles.

About a week afterwards my son sent me.seven of these little ones taken from the stomach of a pollack(Gadus pollachius) which had been caught in a trawl forty miles north-west of St. Ives. On giving them my attention, I was surprised to find they were not the poutassou nor any other Gadus I was acquainted with.
Notes and Memoranda
Authors: E. W. L. H.
Published: May 2009

Aphia pellucida. Nardo, This species has been hitherto known in the Plymouth district from a single example taken at the surface, south of the Mewstone (cf. Cunningham, vol. iii. p. 166). During the present year it has proved to be rather abundant in the estuarine waters, and has also been taken at sea. The following records may be cited:
Notes on the Reproduction of Teleostean Fishes in the South-Western District
Authors: Holt Ernest W. L.
Published: May 2009

These notes are intended to be explanatory of the record of tow-net stages of Teleosteans kept by Mr. S. D. Scott and myself. Although my own name appears alone under the title, it must be understood that the observations were in the sole charge of Mr. Scott until the beginning of March. The record of the 5th April is also Mr. Scott's. The rest were kept by myself. The credit of any scientific result that may accrue from the observations previous to the 30th March belongs therefore solely to Mr. Scott, since his notes and figures are so complete as to render my own share of this part of the work a very simple one.

This journal is not designed for the publication of such profusely illustrated papers as are best suited for the explanation of the earliest stages of Teleosteans. It so happens that in the present instance I am able in most cases to refer either to figures already published, or to others now in the press. A series of notes made at Professor Marion's laboratory at Endoûme, Marseilles, was prepared for the press during 1897. Observations made at Plymouth during the same period were found to have an obvious bearing on the subject-matter of my researches at Marseilles, and by the generous permission of Professor Marion I have been allowed to include in a paper shortly to be published in the Annales du Musée de Marseille a number of drawings made from Playmouth specimens. I am therefore able in many instances to eke out somewhat inadequate descriptions by references to figures in the Annales.
On the Occurrence of large Numbers of Larval Herring at the Surface
Authors: Dunn Matthias
Published: May 2009

“It may interest you to know that on Friday, 14th January, the weather being very fine, and the wind from the S.E., as the fishing-boat Sea Belle (Mr. Blamey, master), was proceeding to the pilchard ground some four or five miles south of the Deadman headland, when about two miles from land they fell in with masses of muddy brown matter in strings, some of which were three or four hundred yards long and form two to seven feet wide, floating quite on the surface. They had not proceeded far along these lanes or path-like forms on the sea before they observed that pilchards were feeding on them ravenously; so they tacked their boat among them for a mile or more, and the further they went the more abundant were the pilchards. About four miles from land and in thirty fathoms of water the anxious gulls indicated the outmost limit of these strangely coloured bands, and here the pilchards were the most plentiful, almost rabid in their mad rush on the lessening streaks, causing the water to boil and whirl violently. Certainly some of the shoals of pilchards could not have had less than thirty to sixty thousand fish in them, for they coloured the water a dark red when concentrated on the brown matter.

“Of course our fisherman expected a more than ordinary catch of pilchards when setting their nets; but, strange to tell, with the decline of the light, having fed to repletion, they sank down below the nets, and the catch was a small one, amounting to some two or three thousand fish.
On the Variation, Races and Migrations of the Mackerel (Scomber scomber)
Authors: Garstang Walter
Published: May 2009

The present investigation was undertaken at the invitation of H.M. Treasury, in consequence of an application to the government from H.M. Inspectors of Irish Fisheries for a scientific investigation into the life-history of the mackerel. The problem to the solution of which the inspectors attached particular importance was the relation to one another of the spring and autumn schools of mackerel which regularly visit the Irish coasts. In the spring a multitude of large fish approach the south and west coasts of Ireland to breed. In the autumn schools of immature, but usually well-grown, mackerel come around the island. According to one of the inspectors, the Rev. W. S. Green, there is a sharply defined interval between the two visitations of fish.
Report on Trawling in Bays on the South Coast of Devon
Authors: Holt Ernest W. L.
Published: May 2009

The investigations dealt with in this memorandum were commenced in the autumn of 1895, and have been carried on, as opportunity permitted, until July of the present year. The observations were made in 1895 and 1896 by Mr. F. B. Stead, in 1897 by Mr. S. D. Scott and myself, and in 1898 by myself. A preliminary memorandum, dealing with the observations made in 1895, has already been submitted to the Committee by Mr. Stead. As a matter of general convenience it is reprinted as an appendix to this Report.
Notes on Pontobdella Muricata
Authors: Gibbs Henry
Published: May 2009

A Pontobdella lived in my tanks for about six months of the present year. I first placed it in a wide shallow tank with a variety of Actiniæ and a few Hermit Crabs, but no fish of any sort. When first introduced the leech was very restless, and wandered all over the tank. After a day or so, however, he took up his abode on the glass, close to the surface. He remained in this spot about three months, and if disturbed would always go back to it. He never noticed any of the other animals, and did not appear in the least sensitive to the stinging power of the tentacles of the Actiniæ. I have frequently seen him plunge his head and neck in amongst the tentacles of a large Anthea cereus who lived near him, and he treated T. crassicornis with a like disrespect.

So soon as the weather grew warm, the leech displayed signs of uneasiness, and finally left his place on the glass, and retired to a cool corner formed by the slate back and side of the tank, close to the syphons of the aerating apparatus, where he remained two months and a half.

He never appeared to notice sticks or nets moving near him in the water, but would remain in his usual position, viz., the base fixed to the wall of the tank, the body sticking out horizontally for about half its length, and the fore part doubled under, so that the mouth was pressed against the under side.
Summary of an Account of Investigations into the Cause or Causes of the Unusual Mortality among Oysters in English Oyster Beds during 1920 and 1921
Authors: Orton J. H.
Published: May 2009

On October 28th, 1920, a conjoint meeting was held by representatives of the Development Commission, the Ministry of Agriculture and Fisheries and the Oyster Merchants and Planters Association to institute investigations into the cause of the abnormal mortality which had occurred among oysters in the oyster beds in the Thames Estuary during the summer of 1920. As a result of this meeting investigations were begun under the general direction of the writer. On the completion of the work a full report of the results obtained was forwarded to the Fisheries Department, Ministry of Agriculture and Fisheries. The more important parts of that report will be published as follows: Part I, Main Report, Fishery Investigations, Ministry of Agriculture and Fisheries, London, Series II, Vol. VI, No. 3, 1923; Part II. containing the more important Appendices, will appear later.
The Phosphate Content of Fresh and Salt Waters in its Relationship to the growth of the Algal Plankton
Authors: Atkins W. R. G.
Published: May 2009

On account of the minute quantities in which they are present and of the fact that they are considered of secondary importance as indicating sewage contamination, phosphates are not usually estimated in analyses of natural waters. The tediousness of the determination also militated against it in the past. As a result, of the numerous analyses recorded by Clarke (1920), but few mention phosphates. C. H. Stone's analysis of the Mississippi in 1905, carried out upon a sample above Carrolton, Louisiana, shows 0.27 per cent of phosphate (PO4) with a total salinity of 146 parts per million, or 0.39 mgrm. PO4per litre, corresponding to 0.29 mgrm. P2O5.
Note on the Oxidisable Organic Matter of Sea Water
Authors: Atkins W. R. G.
Published: May 2009

In a former paper (1922) it was shown that the pH value of stored sea water decreased owing to the production of carbonic acid by organisms in it, and the oxidisable matter as indicated by this biological method appeared to be higher than the result obtained by oxidation with permanganate, according to various analyses available for comparison. These, however, were not done on the same water, so an attempt was made to determine this quantity on water of the English Channel off Plymouth. As is well known the permanganate method gives results which vary appreciably, according to the conditions of the experiment.
Animal Communities of the Level Sea-bottom in the Waters adjacent to Plymouth
Authors: Ford E.
Published: May 2009

From May, 1922, onwards the sq. metre bottom-sampler has been used to collect samples of the bottom-deposits with their animals, in the waters off Plymouth. The animals have been removed as soon as possible after capture by passing the samples through a series of sieves, and have been preserved in alcohol, to be identified and counted ashore. The present report deals with the distribution of the species represented, in the light of Petersen's Community investigations in Danish waters.

I express my thanks to Dr. Allen, Dr. Orton, Mr. Hunt, and Mr. Smith, of the Plymouth Laboratory, for their kind help in the identification of the material. I am particularly indebted to my friend, Mr. R. Winckworth, a late member of the staff, who has not only gone over with me the bulk of my collection of lamellibranchs, but has provided me with an excellent type series as complete as the material would allow.

The extensive use of his bottom-sampler in Danish waters and elsewhere has enabled Dr. C. G. Joh. Petersen to advance an opinion that “as a rule it is best to regard the animals living on the sea-bottom as communities, just as botanists group together the vegetation of the land into plant communities, even though in the present state of our knowledge it is impossible to show how intimate the mutual relations are between the animals of the sea in the single cases.”

It will probably assist the reader if I commence with a short summary recalling the more important points, concerning the recognition of communities, which have been advanced by Peterson, and in doing so I shall adhere closely to his own words.
Note upon an Association between Spider-Crab and Sea-Anemone
Authors: Thomson David Landsborough
Published: May 2009

It was observed during the summer of 1920 that specimens of the Long legged Spider-crab, Stenorhynchus phalangium Penn., which happened to be in the crowded tanks of the Roscoff Laboratory, were always to be found in the neighbourhood of specimens of Anemonia sulcata Penn. (Anthea cereus Ellis). That this was not merely accidental was shown when crabs, removed to a distance of over three feet, returned time after time to an Anemonia, passing on the way anemones of various species, as well as all manner of objects which might conceivably afford shelter. Of fifteen healthy crabs of this species observed during the past three summers, every one showed this tendency in greater or less degree. At least two of these crabs were found clinging to anemones of this species on the shore, between tide marks; but the subsequent behaviour of crabs dredged from deeper water was in no way different.
The Larval Stages of processa canaliculata Leach
Authors: Gurney Robert
Published: May 2009

The material upon which the following account of the development of P.canaliculata is based was mainly obtained in 1902 when working in the Laboratory at Plymouth. The larvæ were first noticed, and their identity suspected, in April of that year, and identification was made certain by keeping the larvæ in the “mysis” stage until they moulted into the post-larval form, some individuals being kept also through several subsequent moults. The intermediate stages were all taken from the plankton, since I was unable to hatch the larvæ from the egg. The only egg-bearing female seen at that time was taken on the Eddystone Ground on April 29, and her eggs were so far advanced that, although she was unfortunately killed, a few larvæ escaped from the eggs and made it possible to obtain some idea of the structure of the first zoæa.

During a short stay in Plymouth during April, 1922,1 was able not only to pick out a few more specimens from the plankton then brought in, but also, by working through a large number of preserved plankton samples, to obtain a considerable amount of additional material, mainly of later stages. A few specimens have also been found in samples of plankton from the North Sea preserved at the Fisheries Laboratory at Lowestoft, for the loan of which I am indebted to Mr. A. C. Hardy. But the larvæ of this species are much rarer in the North Sea than in the neighbourhood of Plymouth, where they are quite common.
Coccolithophora pelagica (Wallich) from the Channel
Authors: Lebour Marie V.
Published: May 2009

A small coccosphere occurs abundantly in centrifuged water samples from the Plymouth district, the western part of the Channel, and outwards towards the Irish Sea and the French coast. This agrees with the species described by Ostenfeld (1899) as Coccosphœra atlantica, from the North Atlantic, which Lohmann (1902) considers identical with Wallich's Coccosphœra pelagica (1877). Lohmann, therefore, unites the two species as Coccolithophora pelagica, and in this he is followed by Ostenfeld (1908), the generic name of Coccosphœra being preoccupied by Perty (1852) for a small green flagellate.

The chief difference between C. pelagica and C. atlantica is in the number of coccoliths (16 to 36 in the former, 10 to 17 in the latter). The overlapping of the margins of the Coccoliths in C. atlantica is another difference, but it appears likely from Wallich's drawings that he had only taken the inner margins into consideration, and, therefore, regarded the coccoliths of C. pelagica as not overlapping. His measurements, which cover an extensive range, embrace those of C. atlantica. It seems, therefore, that C. atlantica is to be regarded as the same species as C. pelagica, the coccoliths having a similar form, and that Lohmann and Ostenfeld are justified in bringing them together.

Coccolithophora pelagica thus includes Murray and Blackman's C. pelagica (1898), Huxley's “Coccospheres” (1868, Plate 4, Figs. 6, c, d, e, and 7, b and c), and Ostenfeld's C. atlantica (1899, 1900). The coccoliths described by Joly and Dixon (1897) and the coccospheres by Dixon (1900) from the Irish Sea also belong to this species.
Studies on Conditioned Responses in Fishes. Part VII. Temperature Perception in Teleosts
Authors: Bull Herbert O.
Published: May 2009

By the use of a “conditioned response” technique it has been shown that teleostean fishes respond “purposively” to an increase in temperature of the water surrounding them of between 0-03° C. and 0-10° C. It is probable that the former figure is true for all the species investigated, but it has only been practicable to establish it with certainty in a few sedentary forms
The Biology ofPurpura Lapillus. I. Shell Variation in Relation to Environment
Authors: Moore Hilary B.
Published: May 2009

By examination of samples of Purpura lapillus from the whole of their European range, it appears that the species can exhibit quite as wide variation within a relatively small region such as that studied in the Dorset-Devon-Cornwall area, as it can over its whole geographic range. Population samples were taken from seventy-six localities, mostly in the south-west of England, and covering a wide range of environmental conditions, and the variations in these shells were studied in relation to two primary environmental factors, degree of exposure to wave-action and diet.
The Occurrence of Diadumene Cincta T. A. Stephenson in the River Roach, Essex
Authors: Rawlinson Ruth
Published: May 2009

Several small anemones resembling Metridium dianthus were collected from the River Roach and sent to me in the summer of 1934. A careful examination proved them to be Diadumene cincta which was first recorded from Plymouth. T. A. Stephenson (1, 1925, p. 880) described both an orange and a fawn variety of this species, the former from the Breakwater and the latter from the Pier, Plymouth. The Roach anemone agrees with the Plymouth one in all its more important habits and its external and internal characters. It would appear that the specimens of D. cincta from the New England Creek, Essex, recorded by T. A. Stephenson (2, 1935) since this account was first written, may have been derived from this river.

The anemones were dredged in abundance from the River Roach attached to living and dead shells of Ostrea and Mytilus and to Alcyonidium and Halichondria. All (about thirty) which I have seen were small, the diameter of the base averaging 0.6 cm. and the disc 1.5 cm. They were orange, but some were pale while others were more deeply coloured. No fawn ones have as yet been found in this locality.

The scapus wall is thin, translucent with a bluish caste and with the mesenterial insertions showing through. The cinclides are evident as distinct dull purple-grey spots, each with a central depression clearly visible under a hand lens. The tentacles are the same colour but paler than the scapus. They are usually uniformly coloured but in some specimens there are two faint bluish lines running along their upper surface and, in one individual, there was a pair of short dashes at their bases instead of these lines.
Additions to the Plymouth Marine Fauna (1931) in the Crustacean OrdersTanaidacea, IsopodaandAmphipoda
Authors: Crawford G. I.
Published: May 2009

Thislist contains 2 species of Tanaidacea, 6 of Isopodaand 28 of Amphipoda. These were all collected by myself in 1934–5, with the exception of 3 species of Amphipoda, which have not been entered in the Plymouth list although accounts of their capture at Plymouth have been published. These areEusirus longipesBoeck, recorded by Hunt (1924);Gammarellus angulosus(Fabr.), by Kitching, Macan and Gilson (1934); andGammarus zaddachiSexton, by Serventy (1935).

The list is drawn up in the systematic order adopted in Plymouth Marine Fauna (1931), with a reference to a good illustration of each species. The dates and circumstances of capture are stated, and when a species has already been recorded from off the coasts of Devon and Cornwall by Norman and Scott (1906) a note to that effect has been made. The distribution is not stated, since recent accounts of the distribution of every species are available in the following works:

Tanaidacea and Isopoda: Nierstrasz and Stekhoven, 1930 (except forSynisoma acuminatana, q.v.).

Amphipoda: Chevreux and Fage (1925) or Stephensen (1929).

All the Amphipod species in this list are included in one or other of these publications, and almost all in both.

Every species has been referred to a specialist for identification. Tanaidacea andEurydice truncataandGnathia oxyurœato J. H. Schuurmans Stekhoven of Utrecht; the other Isopoda to Prof. W. M. Tattersall of Cardiff; the Amphipoda to Dr. K. Stephensen of Copenhagen, exceptingGammarus zaddachiSexton, which Mrs. Sexton herself has named.
Part I. The Object, Plan and Methods of the Investigation
Authors: Hardy A. C.
Published: May 2009

Anumberof naturalists have expressed their belief that the movements of the adult herring (Clupea harengusL.) at certain seasons are governed by the relative abundance or scarcity of their food or other organisms in the plankton.
Part III. The Zooplankton-Herring Correlations in the Scottish Fisheries
Authors: Henderson G. T. D.
Published: May 2009

(1) In the Scottish Eastern and Western Fisheries 459 Plankton Indicator samples have been analysed and the results studied for evidence of correlations between the zooplankton and the 533 associated catches of herring. (See Part IV for the phytoplankton correlations.)

(2) In the Eastern Fishery, 1930-33, out of twenty half-month areaperiods considered of primary value, fifteen show positive Calanus-Herring correlations and five negative. The area-periods of secondary value confirm this three to one ratio, there being eight positive and three negative results indicated. (A three to one ratio was also found in the Shields Fishery. Part II.)

(3) An attempt to estimate the commercial value of the Indicator, when used to locate the richer Calanus waters, shows that if in each period (1931-33) the fishing had taken place in the richer Calanus waters a gain of 24-5 i 7 -7 % over the catch secured by fishing at random should have resulted.
Part-IV. The Relation between Catches of Herring and Phytoplankton Collected by the Plankton Indicator
Authors: Henderson G. T. D. , Lucas C. E. , Fraser J. H.
Published: May 2009

The object of these investigations, discussed in full in Part I, is an attempt to correlate the catches of the drift-net herring fishery with the conditions in the plankton at the time of fishing, and if possible to establish useful indications as to suitable and unsuitable waters for fishing. In Parts II and III the zooplankton-herring correlations in the English and Scottish fisheries have been dealt with separately. The phytoplankton material with which this section deals is not so extensive, so that the data from both fisheries will be dealt with together. The pioneer observations of Pearcey (1885) in regard to the herring, of Bullen (1908) inregard to the mackerel, and the fact that fishermen have for long regarded what they call “weedy” or “stinking” water as a bad sign for fishing, have been referred to in Part I, page 148.
On the Association of Jelly-Fish and Other Organisms with Catches of Herring
Authors: Lucas C. E. , Henderson G. T. D.
Published: May 2009

Investigations into the relations between plankton and herring, using the Hardy Plankton Indicator, were carried out by this department during the years 1930 to 1933 (Hardy, Henderson, Lucas and Fraser, 1936). In planning this work Professor Hardy made provision for obtaininginformation, when possible, on weather conditions and on the occurrence of organisms which would not be caught in the plankton samples. Information on the presence of jelly-fish, was specifically requested. Skippers of drifters using the Indicator were asked to fill in a printed labelfor each disc giving details of ship, date, time, position and catch, and the following sentence was printed at the foot of the label:— “ Any further notes regarding state ofweather, sea, presence of jelly-fish, or any unusual conditions may be written on the back.” Since the details of date, position, catch, etc., were essential for the success of the Indicator experiments, only these were definitely asked for, and skippers were left to supply further information if they had time to do so. Much more exact and extensive information regarding the presence of jelly-fish arid other organisms could have been obtained if the enquiry had been confined to these points, and it is hoped that this may be done in the future, either from thisdepartment or by other workers. Russell (1935, b), in stressing the importance of plankton organisms as indicators of different hydrological conditions, says “it is especially valuableto watch for any correlations between the presence or absence of certain plankton animals with that of fish and larger swimming animals.”
Notes on the Early Stages of two Polychaetes, Nephthys hombergi Lamarck and Pectinaria koreni Malmgren
Authors: Wilson Douglas P.
Published: May 2009

Trochosphekes of Nephthys hombergi Lamarck are readily obtainable at Plymouth when the adult worms are mature from June to September. The worms are dug out of the muddy sand on the lower regions of the shore, and their eggs and sperms obtained by slitting open the body cavity. Fertilizations are easily made in glass finger-bowls of clean sea-water. Although apparently ripe worms have been kept under sea-water circulation in the laboratory, and under a variety of conditions, none has ever been induced to spawn naturally. After some days the body walls of some individuals have split along the back and shed their genital products in that way; these, however, were probably unhealthy and abnormal. A high percentage of the eggs got by cutting open the worms have fertilized and given rise to cultures of strongly swimming larvæ. During the summers of 1932–34 much time and effort were expended in numerous attempts to rear these larvæ, but in no single instance was success obtained. It had been hoped to collect material for a detailed histological study of the development, for it may be of a straightforward and simple type that would throw light on various problems of Polychæte embryology. Although these hopes have not been realized it seems of value to describe the trochosphere of which no entirely satisfactory account exists, in spite of a few references to it by previous writers.
The Ovary as an Indicator of the Spawning Period in Fishes
Authors: Hickling C. F. , Rutenberg E.
Published: May 2009

Accounts of the ovarian development of the eggs of fishes have been given by Kisselevitch (1923). Mayenne (1927), and recently by Hickling (1930) and Raitt (1933). They have concluded that in the ovary of the adult fish there is a general egg-stock of small eggs, yolkless and transparent in fresh material, and with deeply staining cytoplasm in fixed and stained material. From this egg-stock a quota is withdrawn each year to be matured and finally spawned, and to this egg-stock a fresh batch is added each year by the development of oocytes present beneath the surface of the ovigerous lamellæ, the minimum period of development being two seasons.

It has occurred to us that measurements of the diameters of eggs, in ovaries well advanced towards spawning, may give evidence of the duration of spawning in a fish of which the spawning habits are unknown. For where the spawning period is short and definite, the batch of transparent yolkless small eggs, destined to mature and be spawned, will be withdrawn from the general egg-stock in a single group, sharply distinguishable, at least in the later stages of maturation, from the stock of small eggs from which it was derived. But when the spawning period is long and indefinite, the withdrawal of eggs from the egg-stock, to undergo maturation, will be a continuous process, and there will be no sharp separation between the general egg-stock and the maturing eggs. These will pass continuously one into the other. We have tested this hypothesis with four species of fish of known spawning habits.
A Summary of the Work on the AmphipodGammarus CheureuxiSexton Carried out at the Plymouth Laboratory (1912–1936)
Authors: Sexton E. W. , Clark A. R.
Published: May 2009

Thework began in June, 1912, simply as a study of the life-history of some of our common amphipods. The genus Gammarus was chosen, because of the number and the wide distribution of its species in the neighbourhood. Seven of these species, all black-eyed, from marine, estuarine, brackish and fresh waters, were kept in the laboratory for investigation until the first red-eyed specimens were discovered in one of the brackish species, later described asGammarus chevreuxi(see p. 360). Since the manner in which these red-eyed individuals occurred raised points of considerable interest, it was decided to confine investigation toG. chevreuxi, and a series of experiments was started. The different variations involving both the structure and the pigmentation of the body and of the eyes appeared from time to time, some behaving as simple mendelian characters and attributable to the presence of a single recessive gene, others with a more problematical hereditary basis. These variations have been recorded as they occurred (see bibliography). For ten years, no second mutation appeared, although frequent dredgings were made and the animals thus obtained were kept for several generations in laboratory conditions. Because of this apparent stability of character the wild Gammarus was regarded as a homogeneous population until, in 1922, it became increasingly evident that the results showing in the laboratory cultures could only be explained on the supposition that many recessive factors must be present in the natural conditions.

The evidence steadily accumulated, but direct proof was very difficult to obtain partly because (as we found in our experience with the cultures) the recessive types are often less viable than the normal, and therefore probably less able to withstand the competition in the wild, and partly perhaps because we had no criteria by which to assess the influence of the laboratory conditions (changes of temperature, food, salinity, pressure, etc.) on the constitution of the Gammarus, and so could not decide whether a variation was caused by the inherent action of the recessive genes, or by the untoward environment producing a change in the action of the normal genes.
On The Biology Of Glossus Humanus (L.) (Isocardia Cor Lam.)
Authors: Owen G.
Published: May 2009

Glossus humanus (L.) (Isocardia cor Lam.), a large marine eulamellibranch, occurs in deep water in soft muddy substrates. Restriction of the species to a soft substrate is probably correlated with the inflated form of the shell, the weak musculature of the foot, and the poor elastic properties of the ligament.

Growth of the mantle/shell is the resultant of radial, transverse and tangential components, the normal axis being a turbinate spiral. The anterior region of the ligament is progressively split during growth owing to the displacement posteriorly of the secreting surfaces. The relationships of the valves, ligament and mantle isthmus are discussed.

The deeply plicated ctenidia are specialized for dealing with large volumes of water containing little suspended material.

The anatomy and functioning of the stomach is described in detail. There is a complex ciliated mechanism selecting particles on the basis of size. Such a mechanism, it is suggested, must be associated with intracellular digestion. The flap-like major typhlosole prevents material carried by the intestinal groove from returning to the circulation within the stomach, while the retention of an isolated opening for the left pouch is probably correlated with the need for firm fixation of the gastric shield.

Spawning occurs at the end of September.