bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Amphipod Genus Talitrus, with a description of a new species from the Scilly Isles,T. dorrieni n. sp
Authors: Hunt O. D.
Published: May 2009

During the winter of 1924–25 some living specimens of a terrestrial sand-hopper were sent by Major A. A. Dorrien-Smith, D.S.O., Governor of the Isles of Scilly, to Mrs. E. W. Sexton of the Plymouth Laboratory. The specimens, which were handed over to the writer by Mrs. Sexton, have proved on examination to belong to a new species, which is described below and given the nameTalitrus dorrieni.

According to information received with the specimens the species has a truly terrestrial habitat: it is found living among the moist humus and under dead leaves in the gardens of Tresco Abbey.
The Hydrogen Ion Concentration in the Gut of certain Lamellibranchs and Gastropods
Authors: Yonge O. M.
Published: May 2009

1. In the Lamellibranchs, as typified by Pecten maximus, Mya arenaria and Ensis siliqua, the entire, gut has an acid reaction, the stomach being the most acid region and the pH rising along the mid-gut and rectum.

2. The origin of the acidity of the gut lies in the style. This has a low pH (5·4 in Pecten and Mytilus, 4·6 in Ensis and 4·45 in Mya), and, after it has been artificially extracted from Mya or induced to disappear, by keeping the animals under abnormal conditions, in Mytilus, Tapes and Pecten, the pH of the stomach invariably rises (by as much as 0·825 in Mya and 0·72 in Tapes), although the pH in the mantle cavity has fallen.

3. The style, which dissolves rapidly in alkaline or weakly acid media, is not dissolved in fluids below a certain pH—4·4 for Ensis, 4·2 for Mya, 3·6 for Pecten and Mytilus.

4. The style is never absent, even though animals are starved, so long as they are kept under otherwise healthy conditions. The disappearance of the style under abnormal conditions is probably due to a lowering of the vital activities, which include the secretion of the style substance, and the consequent dissolution of the style by the less acid contents of the stomach.

5. The style is only maintained as a result of a balance between the rate of its secretion and the rate of its dissolution.

6. There is a well-marked correlation between the tolerance of the presence of hydrogen ions possessed by the cilia from the various regions of the gut and the degree of acidity of the fluid with which they are normally surrounded.

7. The pH of the gut in five Gastropods has been investigated. The fore-gut and stomach have invariably the lowest pH.

8. This acidity may be caused by the salivary glands (Patella and Buccinum), the digestive gland (Doris and Aplysia), or the style (Crepidula).

9. The mid-gut and rectum have a high pH, except in Doris, where there is little secretion of mucus, the gut being free and muscular.

10. The style of Orepidula has similar properties to those of the Lamellibranchs. It has a pH of 5·8, and is not dissolved in fluid of pH 3·6 or lower.

11. The cilia from the gut of Buccinum and Doris can function in a pH of 5·0, but there is little difference in the toleration of the various cilia to the presence of hydrogen ions.
A Colorimetric Method for Studying the Dissociation of Oxyhæmocyanin suitable for Class Work
Authors: Pantin C. F. A. , Hogben Lancelot T.
Published: May 2009

1. A simple colorimetric method for plotting the dissociation curve of haemocyanin is indicated. The limits of error are within 5 per cent. The simplicity of the method commends it for laboratory class work.

2. The effect of hydrogen ion concentration on the dissociation of the hsemocyanins of the crustaceanPalinurusand the pulmonateHelixhave been compared. In the snail change of hydrogen ion concentration over a wide range was not found to affect the dissociation of the hsemocyanin: in 'the crustacean there is a marked effect similar to that seen in the dissociation of hæmoglobin.

3. The similarity of crustacean hsemocyanin to haemoglobin is also seen in that increasing temperature depresses the dissociation curve. The effects of certain salts upon haemocyanin. have also been recorded.
Further Photo-electric Measurements of the Penetration of Light into Sea-Water
Authors: Poole H. H. , Atkins W. R. G.
Published: May 2009

Further measurements have been made of the penetration of daylight into the sea near Plymouth, photometers containing both vacuum and gas-filled photo-electric cells being used. The effect of obliquity of illumination on the sensitivity of these photometers was large, and has been allowed for as far as possible. The sensitivity of the vacuum cell used in the sea attained its maximum at a wave length of about that of the gas-filled cell at about 4,350. The sensitivity of both to wave lengths greater than 5,500 was small.
Physical Factors on the Sandy Beach. Part I. Tidal, Climatic, and Edaphic
Authors: Ronald Bruce J.
Published: May 2009

The distribution and activities of animals and plants upon the sandy beach are largely influenced by the special physical factors operating in that environment. The paper is a contribution to the knowledge of these factors.

The tidal ebb and flow, and the resulting alternations of exposure, are the outstanding factors. The extent to which other factors may be operative upon the beach, during the period of ebb-tide, depends upon the vertical distance of the point in question above or below mean sea-level.
On Lunar Periodicity in Reproduction of Pecten opercularis near Plymouth in 1927–28
Authors: Amirthalingam C.
Published: May 2009

It has been shown that there is a lunar periodicity in reproduction of P. opercularis near Plymouth in 1927-28. The ripening of sexual products corresponds with the full phase of the moon.

The condition and shape of the gonad changes with the development of the tissues.

The colour, too, of the hermaphrodite organ changes with development.

Black pigmentation has been observed on the gonad in thin-shelled P. opercularis, a phenomenon apparently due to actinic rays penetrating the thin shell.

The breeding season is from January to June inclusive.

The gut contents seem to show no appreciable difference either in quantity or in the natureof the food during a lunar month.

The moonlight has apparently no effect on the lunar periodicity in reproduction.

It is suggested that in the animal there is a physiological rhythm that causes the development of the gonad to coincide with the full moon of each lunar month
Contributions to the Study of Relative Growth in Gammarus cheureuxi.
Authors: Kunkel B. W. , Robertson J. A.
Published: May 2009

The following two sections represent two preliminary communications to the study of relative growth in a small Crustacean admirably adapted for use as a laboratory animal in all studies involving growth and development.
The Food of Plankton Organisms
Authors: Lebour Marie V.
Published: May 2009

Following the researches on the food of young fishes, it was thought advisable to investigate the food of the planktonic invertebrates. Whenever possible, therefore, the food of the larger animals brought in by the tow-nets was noted, and also that of many of the smaller creatures down to some of the unicellular organisms, such as the tintinnids and those members of the Peridiniales which are holozoic.

With the larger animals it was hoped to find which of them actually ate the young fishes, and by investigating their food in general ascertain how much they were actually competitors with the fishes.

The present work is offered as a preliminary, and it is hoped to continue it, following it up especially with more experimental work on the living animals.

The tow-nettings were examined fresh and the food noted. Sometimes a few hours elapsed between the taking of the sample and the examination, so that some of the catch was moribund in the jar. There is always the objection that the food might have been taken in the jar whilst the plankton was being brought in, and it is a matter of general observation that many medusæ and various pelagic animals will devour young fishes and almost anything living when crowded up with them in the hauls. In many of the organisms examined, however, the nature of the food was so consistent in various hauls and from various localities that it seems almost impossible to believe that it is merely accidental, and it is probable that what food one usually finds inside any planktonic animal is natural to it.
Di Brom Thymol Sulhpone Phthalein as a Reagent for Determining the Hydrogen Ion Concentration of Living Cells
Authors: Atkins W. R. G.
Published: May 2009

1. Brom thymol blue may be used in dilute solution for ascertaining the hydrogen ion concentration of certain marine organisms. It penetrates slowly, but the stained portions remain actively motile, so its toxic action does not appear to be great at the dilutions found serviceable.

2. The animals studied gave values from pH6·2 to about pH7·5, though possibly the more alkaline end of the range may be pathological. About pH0·2 should be subtracted from these figures for neutral salt error. The sea water used was initially at pH8·2, corrected.
Plymouth Peridinians: I. Diplopsalis Lenticula and its Relatives
Authors: Lebour Marie V.
Published: May 2009

Much discussion has recently taken place over the peridinian described by Bergh (1882) as Diplopsalis lenticula, and certainly three distinct species have severally been designated as the original. As it is a name frequently to be found in the International Plankton lists, it is important that we should be clear as to which species we are noting, and as recent research at Plymouth has shown that all the three are common in the district it seems worth while to investigate them once more. The question is interesting also from the point of view of phylogeny, as in these species we have close relatives of Peridinium proper which seem to indicate the method of evolution of that genus from simpler forms with fewer plates, and from this point of view alone they are well worth study.
Plymouth Peridinians: II. Exuviella Perforata Gran from the English Channel
Authors: Lebour Marie V.
Published: May 2009

In centrifuging samples of sea water from Plymouth Sound and some of the stations outside, some interesting forms of Exuviella were found. These are all minute, the largest measuring 22 µ in length, and consequently are easily overlooked, although one at least is abundant during the summer months. This species, which is the commonest Exuviella in the Plymouth district, has been identified as Exuviella perforata Gran, described by him from the North Sea (1915), and is a new record for the English Channel. As it appears to be very little known and its structure is unusual in several particulars, the following notes are not without interest.

In 1915 Gran (page 99, Fig. 7) describes and figures Exuviella perforata, a new species from the North Sea at a depth of 0–20 metres, occurring in the eastern part with a density of 100–760 specimens per litre. It is roundish oval or nearly circular in shape, measuring 22.5–25 µ long and 21–22.5 µ wide, with a broad girdle and thick shell (thickness of cell 14–17 µ). The character, however, that gives it peculiar distinction is the depression in the centre of each valve, as Gran puts it, “with a sharply confined point-shaped perforated deepening in the centre.” This separates it from any previously known species of Exuviella. The cell contents owing to contraction could not be described in detail, but in a footnote it is stated that living specimens from Arendal in March, 1914, had brown chromatophores. Cleve-Euler (1917) records an Exuviella, which he says may be E. perforata Gran, as occurring frequently in the Skaggerak, from 0 to 100 metres.
Plymouth Peridinians: III. A New Species of Phalacroma
Authors: Lebour Marie V.
Published: May 2009

In centrifuged water and in very fine tow-nets there sometimes occurred an extremely small species of Phalacroma, which appears to be new.
The Biology ofBalanus balanoides. II. Algal Infection of the Shell
Authors: Parke M. W. , Moore H. B.
Published: May 2009

Inwork on the biology ofBalanus balanoides, use has been made of the method of differentiating the successive year groups by the colour of their shells. The present paper describes the method of doing this, and gives a brief account of the infective penetrative algæ which cause the colouration. The first author (M.W.P.) is responsible for the algological observations, and the second (H.B.M.) for the zoological observations.
The Growth Rate of Balanus hameri (Ascanius)
Authors: Moore Hilary B.
Published: May 2009

1. Sixty specimens of B. haineri, of five successive year groups, were obtained in December, 1933, and a further 33 preserved specimens taken in the winter of 1925 were examined.

2. The mean ages contained for successive year groups from the size distribution and from individuals settled on those of the preceding year, yielded results in good agreement with one another.

3. First-year individuals do not spawn. All older individuals had ripe genital products in the 1933 material, and early embryos in the 1925 material.
A Case of Hermaphroditism and Viviparity in Echinocardium cordatum
Authors: Moore Hilary B.
Published: May 2009

In May, 1933, during routine gonad examinations, a hermaphrodite specimen of Echinocardium cordatum was observed. It was collected in the sandy beach of Port Erin Bay at low water of ordinary spring tides, and was 4.7 cm. in length, which corresponds, in a normal specimen, to an age of about four years. The external colour was dark, although not more so than in other specimens in the batch, but the gonad was exceptionally pigmented—almost black. In this locality the colour of the test and gonad becomes progressively darker with increasing age, and affords some measure of the latter.

The specimen was examined within half an hour of being collected, and portions of the gonad were fixed within ten minutes of being opened, so that fertilization and segmentation could not have advanced in the laboratory to the stage found. Smears from the gonad showed ova, of which about 50% were ripe, together with ripe spermatozoa. The gonoduct contained ripe ova, together with segmenting ova and early embryos. Figure 1 is a photograph of the contents of the gonoduct, taken immediately after opening, and showing ova with a four-cell stage and a blastula. Cultures were set up in sterile sea-water, from the contents of the gonoduct, and also from the gonad itself, as well as a control fertilization from normal urchins, and from all of these normal early plutei were reared. Those cultures from the hermaphrodite specimen did not, however, develop much further, possibly owing to premature fertilization in the abnormal conditions in the gonad.
The use of trawl, grab and camera in estimating marine benthos
Authors: McIntyre A. D.
Published: May 2009

Certain animals of the epifauna, because of their distribution over the bottom, are often difficult to sample quantitatively. They may occur as individuals widely dispersed over a large area, or they may be present in dense aggregations which themselves have a patchy distribution. In the past, workers have tried to estimate the numbers of such animals by the combined use of trawls and grabs of various types. The post-war development of underwater photography suggests that the camera will be a useful additional tool (e.g. Vevers, 1951, 1952). During the testing of an underwater camera from Aberdeen an opportunity was taken to compare the estimates of some of the larger epifauna from grab and trawl hauls with estimates derived from underwater photographs. The results are described in this paper.
Strontium and barium in sea water and marine organisms
Authors: Bowen H. J. M.
Published: May 2009

Since the advent of nuclear fission, considerable interest has been aroused in the biological fate of strontium, as two isotopes of this element are among the longer-lived fission products of uranium. Strontium 90, in particular, constitutes the major hazard in old fission products because it is readily taken up by all kinds of plants and may then be concentrated in the bones of animals feeding on the plants. Strontium 90 contamination may be derived from fall-out from atomic explosions or from uncontrolled disposal of fission products. The oceans should receive more than twice as much Strontium 90 from fall-out as the continents because 70% of the surface area of the globe is covered by sea. The oceans are also used, though to a very limited extent at present, for the disposal of fission products from reactor wastes. Hence it is obviously important to study the behaviour of strontium in marine organisms in order to evaluate the health hazard caused by controlled or uncontrolled radioactive contamination of sea water. Barium has only relatively short-lived fission-product isotopes, but can readily be studied at the same time as strontium because of its similar chemistry.
Planktonic evidence for irregular flow through the Irish Sea and North Channel in the autumn of 1954
Authors: Williamson D. I.
Published: May 2009

During the autumn of 1954 plankton samples were taken in the northern Irish Sea and the North Channel from R.V. Clupea (Scottish Home Department) as part of a larger survey of the distribution of herring larvae. At the same period similar samples were taken in the central Irish Sea from R. V. William Herdman (Marine Biological Station, Port Erin). The present paper concerns the distribution, as shown by both sets of samples, of a few selected species.

I am indebted to all those on both vessels who assisted in taking the samples and to the Marine Laboratory, Aberdeen, for lending me for analysis the samples taken from R.V. Clupea.
On a pelagic penaeid prawn,Funchalia woodwardiJohnson, new to the British fauna
Authors: Gordon Isabella , Ingle R. W.
Published: May 2009

On 30 July 1955 Dr J. H. Fraser, of the Scottish Home Department, Marine Laboratory, Aberdeen, sent to the British Museum for determination two adult females of a penaeid prawn collected at 01.56–02.0 h B.S.T. near the surface (15 fm.) at Rosemary Knoll, to the north-west of the Outer Hebrides, on 22 July 1955. The actual depth at this locality, 59° 12′ N., 10° 09′ W., is 229 fm (419 m). These specimens were identified by one of us (R. W. I.) asFunchalia woodwardiJohnson. Later the senior author confirmed this determination and wrote to Dr Fraser as follows:
On two new medusae, Merga reesi n.sp. and Tiaropsidium atlanticum n.sp.
Authors: Russell F. S.
Published: May 2009

In a collection made with a 2 m stramin ring trawl at 47° 12′ N., 7° 40′ W. on 21 July 1955, with 450 fathoms of wire out, I have found two new species of medusae. These were each represented by a single specimen, one of which was an anthomedusa and the other a leptomedusa.
The tidal rhythm and action of the digestive system of the lamellibranchLasaea rubra
Authors: Morton J. E.
Published: May 2009

It has been well established that some of the features of the feeding and digestive process in molluscs are rhythmic in character. Notably Hirsch (1915, 1917, 1931) has demonstrated a rhythmic periodicity of secretion in the salivary glands and digestive glands of some carnivorous Gastropoda, and Krijgsman (1925, 1928) has done similar work on the land pulmonateHelix. In all of these animals—and in cephalopods, too, where there is a more elaborate nervous control of secretion—discontinuous feeding is the rule. In the other and perhaps larger category of molluscs—those continuously feeding on fine particles—the central mechanism of the gut is the crystalline style, or its forerunner the protostyle. Here the need is, in Yonge's words (1937), ‘to the extent to which they depend on extracellular enzymes for digestion, continuous secretion’. In Yonge's view, now classical, the style was regarded as ‘an ideal mechanism for the continuous liberation of small quantities of an amylolytic enzyme’. Graham (1939), in his work on style-bearing gastropods, showed that the style is in general confined to animals with a continuous feeding habit, whether by ciliary means or by using the radula to graze on and rasp off fine particles. It is known that style secretion stops and the style is frequentiy dissolved when animals are removed from the water and cease feeding (see Yonge, 1925).
The bacterial oxidation of ammonia in the sea
Authors: Spencer C. P.
Published: May 2009

The final regeneration stages of the nitrogen cycle in the sea are believed to consist of the bacterial oxidation of ammonium-nitrogen to nitrite and finally nitrate-nitrogen. There have been many attempts to demonstrate the presence in the sea of marine counterparts to the terrestrial Nitrosomonas and Nttrobacter. (See Zobell, 1946, for bibliography of the earlier work.) Bacteria which can oxidize either ammonia or nitrite are easily demonstrated in samples of bottom material or water contaminated by land drainage or bottom deposits. On the other hand, there has been general failure to demonstrate the presence of such species in the upper layers of the open ocean.
Evidence of self-fertilization in certain species of barnacles
Authors: Barnes H. , Crisp D. J.
Published: May 2009

Isolated individuals of certain species of cirripedes are known to remain unfertilized at the time when the majority of contiguous individuals are carrying egg masses. From a very large number of observations on both Balanus balanoides (L.) and Elminius modestus Darwin (Crisp, 1950, 1956) there remains little doubt that in these two species copulation is necessary before eggs are brought into the mantle cavity where they are fertilized. Though fewer field observations have been made, Balanus crenatus Bruguière appears to behave similarly, isolated specimens grown on raft-exposed panels never bearing fertilized egg masses (Crisp, 1950; Barnes, unpublished observation). B. balanus (L.) (= B. porcatus da Costa) is also in all probability an obligatory cross-fertilizing hermaphrodite, though the available evidence does not exclude the possibility of self-fertilization in rare instances (Crisp, 1954; Barnes & Barnes, 1954).
Preliminary Notes on the Reproduction of Teleostean Fishes in the South-Western District
Authors: Holt Ernest W. L.
Published: May 2009

During the present year tow-netting has been carried on with such continuity as the weather permitted, and the fish-ova and larvæ thereby obtained have been studied by Mr. S. D. Scott during the winter months, and by myself since the spring. While reserving a general account of the results until the close of the season, it seems advisable to deal now, in however preliminary a manner, with a few species, an addition to the existing knowledge of which may be found of immediate use by workers in the same field. I take this opportunity of expressing my indebtedness to Mr. Scott for observing certain eggs which I was obliged to leave at the Laboratory at a stage too little advanced for specific determination.
Director's Report
Authors: Allen E. J.
Published: May 2009

As announced in the Report of the Council for 1896–97 (p. 100), important changes have taken place in the staff of naturalists working for the Association. Mr. Garstang, who now has charge of the fishery investigations, commenced his new duties in June; and Mr. E. W. L. Holt, who has placed his services, for the time being, at the disposal of the Association, has been occupied with researches on food fishes since March last. It is much to be desired that the staff should be maintained at at least its present strength, but unfortunately the conditions of Mr. Holt's appointment, which is purely honorary, preclude the possibility of our hoping that this may be the case, unless funds can be provided to give him a position of a more permanent character. It will be remembered that it was only through private generosity that the Association was able for a number of years to retain the services of two naturalists for fishery investigations, and although we have the good fortune for the present to maintain this condition of things, the possibility of the reduction of the number is a prospect which cannot but be regarded as most serious for the future welfare of the Association. It would be exceedingly unfortunate if from the want of funds to remunerate his services the really valuable work which Mr. Holt is now doing for the Association were to be stopped.
Inspection of the Laboratory.
Authors: Lankester E. Ray , Beddard F. E.
Published: May 2009

The Laboratory was visited and inspected on June 26th and 27th by a Committee appointed by the Council for that purpose, and the following report was submitted to the Council at the meeting held on June 29th:—

“The Committee, consisting of the President and Mr. Beddard, arrived in Plymouth on Saturday, June 26th. They visited the laboratories, engine-rooms, tank-room, library, and museum on both Saturday and Sunday. By the President's invitation, they were joined at Plymouth by Mr. John Enys, of Enys, near Falmouth, a member of the Association.

“The Committee report in the first place that the satisfactory standard of general efficiency noted last year has been fully maintained. The place is in excellent condition, clean and orderly, and the servants are well in hand.

“The large laboratory has been provided with a new flat tank, eight feet by five feet and eight inches deep, by aid of which Mr. Garstang has been carrying on some observations on the habits of Brachyurous Crustacea. The sea-water supplied to the laboratory is still kept distinct from the general circulation in the show tanks, and is never returned to the laboratory tanks after it has passed through them. We are of opinion that this is the only satisfactory system for maintaining marine organisms in a really healthy condition in confinement, the whole theory of ‘circulation’ being illusory and in practice disastrous.

“The lecture-room is in good order, and has proved to be very useful and well fitted for its purpose.

“The collection of local types in the museum has progressed.
Preliminary Report on the Results of Statistical and Ichthyological Investigations made at the Plymouth Laboratory
Authors: Duncker Georg
Published: May 2009

During my stay, from August to October, 1897, at the Laboratory of the Marine Biological Association of the United Kingdom, I was especially engaged in investigating the variability of Pleuronectes flesus, Linn., and Siphonostoma typhle, Linn. Of the results so obtained, some of more local faunistic importance are briefly reported here.
The “Bottle-nose Ray” (? R. alba, Lacép.) and its Egg-purse.
Authors: Holt Ernest W. L.
Published: May 2009

For a number of years our tanks have from time to time contained a very large and easily-recognised Skate-purse, but its specific identity has remained a matter of uncertainty. Fishermen attributed it to the “Bottle-nose ray”, a species not to be found, so far as I am aware, in ichthyological works.
Notes and Memoranda
Authors: E. W. L. H.  , W. G.
Published: May 2009

The common wrasse of our coasts is well known to exhibit, as a species, an almost endless variation of colour. To what extent the different colour-patterns are individual or congenital, and to what extent they may be produced in the same individual by different stimuli, appears to be a question worthy of careful examination. We propose at present to deal chiefly with the observation of a single specimen.
Report on the Surface Drift of the English Channel and neighbouring Seas during 1897.
Authors: Garstang Walter
Published: May 2009

I. Introduction.

Some eighteen months ago the Director of the Plymouth Laboratory of the Marine Biological Association decided to carry out a series of investigations concerning the surface currents of the English Channel at different seasons of the year, and for a series of years, by means of properly devised floating bodies which would attract attention when standed on the shore, and the recovery of which could without difficulty be recorded. At the commencement of the investigation Mr. Allen communicated his scheme to the editors of the west-country Press, and these gentlemen kindly gave publicity to the plan, the success of which depended very largely upon the co-operation of residents and visitors frequenting the sea-shore. Mr. Allen's letter expresses so clearly the object and method of the investigation, that I cannot do better than reproduce it here:—
Notes on the Reproduction of Teleostean Fishes in the South-Western District.
Authors: Holt Ernest W. L. , Byrne L. W.
Published: May 2009

Morone labrax. Linn. Bass.

Towards the end of May a large female bass in one of the Aquarium tanks appeared to be approaching ripeness, and constantly swam round the tank followed by one or more of its companions, probably of the opposite sex. A fine-meshed net was accordingly placed over the overflow from the tank in question, and on the morning of the 29th May was found to contain a very large number of eggs, undoubtedly attributable to this species, the only other Teleostean inmates being turbot, congers, pollack, rocklings, and two species of wrasse.

All the eggs proved to be unfertilised, or, at most, showed only an approach to segmentation, which may have been due to the spermatozoa of a rockling. Circumstances seemed strongly to point to the fact that the eggs are not all shed at once, but owing to an unfortunate series of accidents with the net it is impossible to speak on this point with absolute certainty.

Although the bass is a common British fish, its ova find no place in the records of British naturalists, and are only known from the descriptions of Raffaele, who obtained them both from parents living in the tanks of the Naples Laboratory and from the neighbouring sea.

The eggs observed by us at Plymouth are spherical, and, while living but unfertilised, measure from 1·25 to 1·34 mm in diameter. Raffaele gives 1·155 to 1·2 mm as the diameter of Naples examples. The latter have an oil-globule of ·332 to ·366 mm.
The Hydrogen Ion Concentration of Sea Water in its Relation to Photosynthetic Changes. Part II
Authors: Atkins W. R. G.
Published: May 2009

In the first publication under the above general title the seasonal changes in sea water were studied, but as explained previously it was not possible to regard all the data as of an equal degree of accuracy. For this and other reasons the seasonal changes were further traced in the hydrographical cruises up to October, 1922, when the approach of the winter equilibrium made it profitless for some months to continue. Since, however, at times from April to September the changes are relatively rapid it may be advisable to follow up the matter during the period mentioned at shorter intervals.
The Relation between Catches of Mackerel and the Surface Temperature in situ
Authors: Lumby J. R.
Published: May 2009

The short investigation here described was made in March and April, 1922, during the spring mackerel fishing season off the Cornish coast, in order to discover whether the opinion of Skipper Wylie, of Lowestoft, (drifter, Realize) was justified. In his opinion the best catches of mackerel were made wherever his thermometer showed him a sea surface temperature higher than that of the neighbouring water.

About a dozen drifter skippers, who volunteered to undertake the work, were given thermometers, graduated in ⅕° C. (about 20 graduations per cm.) and forms upon which to record their observations, and were shown how to take a surface sample and read its temperature. These thermometers were not very suitable, since the range was too great, and therefore the scale too small. They also suffered from the defect that the mercury thread easily become broken, and if the detached portion ran down into the bulb at the top of the tube, it was difficult to ensure that all the mercury came out again, and that the thread made a proper joint.

The forms used (p. 241) were based upon the log books used during the investigations on pelagic fishes from 1895 to 1911* (Russell, 1915). It was hoped that sufficient data would be collected in the course of a month, but, although the experiment was extended into April, only 32 records are available, covering the period 9th March-19th April.

These records are tabulated in Table 1. In those cases where the temperatures at the times of shooting and hauling differed, both the values are given, but their mean has been used in computing averages.
On Rearing the Hydroid Zanclea Implexa (Alder) and its Medusa Zanclea Gemmosa McCrady, with a Review of the Genus Zanclea
Authors: Russell F. S. , Rees W. J.
Published: May 2009

Descriptions of the hydroid Zanclea implexa (Alder) in British waters have been given by the following authors, Alder (1857, as Tubularia implexa and Coryne pelagica), Allman (1859, as Coryne Briareus), Strethill Wright (1859) and Alder (1862 as Coryne implexa), Allman (1864 as Zanclea implexa and 1872 as Gemmaria implexa) and Hincks (1872, as Zanclea (Gemmaria) implexa). All these descriptions have been based upon full grown colonies in which the hydranths had a perisarc on the hydrocaulus.
On the First Stage of the Medusa Eucheilota Clausa (Hincks)[= E. Hartlaubi Russell]
Authors: Russell F. S.
Published: May 2009

In the last number of this Journal (Russell, 1936) I described under the name Eucheilota hartlaubi the adult and various stages of a medusa that is fairly common in the Plymouth plankton but had up till then remained undescribed. This medusa was identified with an unnamed medusa which Hartlaub had figured as having been reared from the hydroid Lovénella clausa Lovén.

On March 10th, 1936, some Lovénella clausa kept in this laboratory by Mr. W. J. Rees liberated medusæ. Mr. Rees kindly handed these over to me so that I could follow the early development. When first liberated the medusa was conically bell-shaped (Fig. 1) and there were scattered nematocysts on the exumbrella. There were two fully developed opposite perradialtentacles, and two non-tentacular perradial bulbs. Rudiments of spiral cirri were developing on either side of the tentacular bulbs. There were four interradial marginal cirri each of which was situated on the umbrella margin about midway between the tentacular and nontentacular bulbs.On the tentacle sides of each of these marginal cirri was a marginal vesicle with a single concretion. The medusa was 0.75 mm. high by 0.75 mm. broad. The colour of the tentacular and non-tentacular bulbs and the stomach was pale straw. By the next day the umbrella had assumed amore oval bell-shape and the colour of the bulbs and stomach was now a bright orange-yellow. OnMarch 12th the medusa was now 0.9 mm. high and the rudiments of cirri were developing on one side of each non-tentacular bulb (Fig. 2).
On a New Species of Hydroid, Staurocoryne Filiformis, with a Revision of the Genus Staurocoryne Rotch, 1872
Authors: Rees W. J.
Published: May 2009

The writer has recently reared a species of hydroid at Plymouth, which, in the vegetative state, might easily be confused with Slauridium productum Wright, 1858. The original creeping stolon from which the colony developed was found on a piece of dead Eunicella verrucosa (Pallas) dredged by the S.S.Salpa near Stoke Point on March 9th, 1936.

When isolated in a finger-bowl with “outside” sea water the stolon bore no polyps and showed no sign of activity, but three weeks later a single polyp had developed (Fig. 3). From its close resemblance to the figures given by Hartlaub (1895) for S. productum, it was at first assumed to be this species and was carefully watched and fed in the hope of rearing the medusæ from it. After a period of time, however, when the colony had increased considerably in size, styloid gonophores were developed.

The type of growth of the fully grown colony is shown in Figures 1 and 2. The stems are elongated and slender, bearing polyps at intervals. Polyps are borne at the summit and also on branches of the main stems. These branches usually arise from one side only of the main stems and it is probable that under natural conditions in the sea these main stems are really stolons. It is also likely that in nature the intervals between the polyps are fairly short. The whole colony has a faint yellow-brown colour which becomes reddish-brown in the polyps and the upper part of the hydrocaulus.
Heterozygotes in a Wild Population of Gammarus cheureuxi Sexton
Authors: Sexton E. W. , Clark. A. R.
Published: May 2009

During the progress of the work on Gammarus chevreuzi it became increasingly evident that heterozygosity must exist in the wild population.
The Biomass of the Bottom Fauna in the English Channel off Plymouth
Authors: Holme N. A.
Published: May 2009

A survey has been made of the biomass of the macrobenthos at twenty stations in the English Channel off Plymouth. The object was to provide a basis for following long-term fluctuations in the fauna.

A brief survey of physical conditions in the area is given, and a gradeanalysis of the soil at each station has been made.

Core-samples show that the sediment is shallow in many places and rock has been taken at 36 cm. or less below the surface at a number of stations.

Samples totalling ½m.2 were taken at each station with a modified 'scoopsampler', covering 1/10m.2, which is briefly described.

Sources of error in sampling are considered in detail. Some species may evade the sampler and others live too deep in the sediment to be taken. A comparison against a Petersen grab and a new ' suction-corer' show that the scoop-sampler does take a reasonably quantitative sample. The number of species taken in successive hauls, when plotted against the log of the area sampled, approaches a straight-line relationship similar to that obtained by Williams (1950).

A statistical analysis is made of a series of samples taken at one station, and the variance between the two samples in each haul and between successive hauls calculated. At this pàrticular station the fauna in successive samples is shown to be fairly random.

A sieve of 2-2 mm. mesh was employed. Compared with a finer sieve losses in terms of numbers may be quite large, but the total weight taken is little affected.
Defaecation in Relation to The Spontaneous Activity Cycles ofArenicola MarinaL.
Authors: Wells G. P.
Published: May 2009

The behaviour of lugworms in sand was studied by recording kymographically the water movements through their burrows and observing the timing of defaecation. The worms ranged in weight from 2 6 to 186 g. Three types of apparatus were used, differing in the amount of space allowed to the worms.

The worms often traced a characteristic pattern described elsewhere, consisting of regularly spaced diphasic excursions of the irrigation graph with a defaecation on the apex of each first phase. The interval between excursions was about 15–20 min. for worms weighing about 3 g. and increased with size to about 40 min.

The worms sometimes traced similar periodic bursts of irrigation activity without defaecation.

Many of the tracings were confused in pattern. The worms often defaecated—sometimes sporadically, sometimes at regular intervals—in the absence of the characteristic diphasic excursions. Restriction of a worm to a small space appears to favour the production of confused tracings.

The relation between the irrigation patterns and the timing of defaecation is discussed.
Luminescence in Polynoid Worms
Authors: Nicol J. A. C.
Published: May 2009

Six species of luminescent polynoids of the Plymouth fauna have been studied, namely Lagisca extenuata, Gattyana cirrosa, Harmothoë liinulata, Polynoë scolopendrina, Acholoë astericola and Malmgrenia castanea. Their scales are luminescent, and the light is produced by granular eosinophilic photocytes, which form a unicellular layer on the lower surface of the scale. The nervous supply of the elytrum is described, and the luminescent response is shown to be under nervous control. Luminescent responses from all six species have been recorded by the use of a photomultiplier cell and oscilloscope. The normal response has been found to consist of a series of rhythmic flashes, from 9 to 1 per sec, lasting up to 1 min. Some characteristics of the luminescent responses are given, and the part they may play in the normal life of the animal is discussed.
Comparison of the Different Methods of Estimating Nanoplankton
Authors: Dorothy Ballantine
Published: May 2009

Six methods for estimating the numbers of nanoplankton organisms in sea water have been compared. Of these, centrifugation of a living sample, followed by counts of the numbers of organisms in the concentrate, appears to be the most satisfactory method from all points of view. The method is rapid, simple to operate, and gives a result which is strictly comparable with results from counts made under dark-ground illumination of unconcentrated samples, and from counts after concentrating with niters. By this method the organisms counted can usually be assigned to the class and order to which they belong, even if their systematic position cannot be determined more definitely.

The use of species-pure cultures is a necessary adjunct to the direct examination of sea-water samples when studying the distribution, abundance, and annual fluctuations of nanoplankton, as so little is known of the systematics of these organisms.
The Feeding Habits of Plaice Post-Larvae in the Southern Bight
Authors: Shelbourne J. E.
Published: May 2009

An examination was made of the stomach contents of plaice post-larvae taken from the Southern Bight spawning ground in the spring of 1950. They were found to be feeding mainly on a soft-bodied prey, which left characteristically shaped faecal pellets and an undigested matrix vesicle as the only evidence of its nature. Pellets from the post-larvae compared closely in shape with those of Oikopleura dioica, found in the plankton of the spawning area during the period of post-larval development.

In 1951, undigested Oikopleura were seen in the oesophageal regions of a few dissected specimens, in addition to typical indigestible remains in a large proportion of the total feeding post-larvae examined.

Records for 1946 suggest a similar exploitation of the Oikopleura population by plaice post-larvae, although the phenomenon was not repeated in 1947, when inclement weather may have interfered with the annual outburst of this prey.

The phenomenon of food selection by plaice post-larvae is discussed, with special reference to the part that vulnerability may play in limiting the number of species of prey available as food.

A feature of this and other investigations on post-larval feeding, was the occurrence of a high proportion of empty stomachs. An experiment designed to test a regurgitation hypothesis, revealed the existence of a marked diurnal pattern of feeding activity, apparently influenced by light conditions. The importance of light in feeding behaviour was confirmed by tank experiments. In this investigation a large proportion of the empty stomachs encountered can be explained by reference to diurnal fluctuations in feeding activity, supporting the view that plaice post-larvae are visual feeders.
The Settlement of Ophelia Bicornis Savigny Larvae The 1952 Experiments
Authors: Wilson Douglas P.
Published: May 2009

Previous conclusions that it should be possible to forecast the intensity of settlements which will be obtained in fifty-fifty mixture of two sands, provided the relative attractiveness or repellence of each component is known, were fully confirmed. The results of these mixture experiments agree with the classification of sands as attractive, neutral or repellent.

It is shown that an attractive factor is capable of transference, in sea water, from fresh Bullhill Bank sand to acid-cleaned quartz sands, to calcareous oolitic sand and to an artificial sand of fused alumina. The attractive factor is present in water in which fresh Bullhill Bank sand had been shaken.

A similar transference of a repellent factor from fresh Salthouse Lake sand is not so clearly demonstrable. Water in which fresh Salthouse Lake sand has been shaken appears to contain the attractive factor. Thus both attractive and repellent factors may be present in Salthouse Lake sand.

Activated charcoal stimulates larvae to settle and metamorphose, but needs to be in granular form, or associated with neutral grains, to exert its full influence. The charcoal contains copper in minute proportion, but whether this has any significance for metamorphosis is undetermined.

The grade of a sand was again shown to be a settlement factor of some importance. The most attractive grain sizes appear to be those of which the bulk of the Bullhill Bank surface sand is composed.

Analysis shows that the surface sand of Salthouse Lake (St. II) contains some three times the organic nitrogen content of the surface sand of the Bullhill Bank.
Notes on the British Species of Trididemnum (Didemnidae, Ascidiacea), With A Report Of The Occurrence Of T. Niveum (Giard) in the Plymouth area
Authors: Carlisle D. B.
Published: May 2009

The presence of Trididemnum niveum (Giard) is reported from the Plymouth area. It is compared with the other two British species of Trididemnum, T. tenerum and T. alleni, with which it has in the past been somewhat confused, and all three are shown to be distinct species. A short diagnosis of the three species is given as an aid to identification.
Cercaria ReesiN.Sp., A New Furcocercous Larva From Plymouth
Authors: Hutton Robert F.
Published: May 2009

A new longifurcous, pharyngeate, distome cercaria has been found to develop in the marine bivalvesHiatella arctica(L.) andH. striataFleuriau. This larva was present in 12 of 200 specimens ofH. arcticacollected from Drake's Island during the summer months (May-August) of 1952,.while the same parasite was found in 15 of 100 specimens of the limestone borer,H. striata,dredged from Plymouth Sound during June and July of the same year.
Notes on the Pycnogonida of Plymouth
Authors: Lebour Marie V.
Published: May 2009

The Pycnogonida of Plymouth have had very little attention and early records are few. Of the eight species recorded in the Plymouth Marine Invertebrate Fauna in 1904, two, Nymphon gallicum and N. gracile, are synonymous, and these two are also recorded in the 1931 edition which comprises only the same eight species. The scarcity of the records shows that little search was made for the members of this group, for on revising it at the present time it is found that thirteen species certainly occur, being five more than are shown in the Marine Invertebrate Fauna. Hodgson (1910) records thirteen species from Devonshire, but these are not all the same as the thirteen now recorded. He mentions eleven from Plymouth, three of which have not been found recently. These are Pallene spectrum, Nymphon brevirostre and Ammothea laevis.
Marking Fish with the Electric Tattooing Needle
Authors: Hickling C. F.
Published: May 2009

Most fishery biologists have heard from time to time of experiments on marking fish by tattooing identification marks on them. The present usual methods of marking fish by attaching marks externally to the gill-cover, caudal peduncle, or other part of the body, have the disadvantage that a certain number of the marks are lost, and this uncertainty bedevils all those marking experiments designed to show rates of mortality or rates of capture.

Yet the only reference in the literature known to me is a very short paper by Gandolfi-Hornyold (1929). His most successful experiment consisted in marking six silver eels on the light ventral side withIndian ink (encre de Chine) introduced in the oriental fashion by a bundle of needles. Five of the six fish were alive some 6 weeks later with the marks as clearly legible as when first made. But I know of no further developments of this technique

In August 1939, I made some experiments at the Plymouth Laboratory, by the courtesy of the late Director, Dr Kemp, F.R.S., and with the help of the staff, to all of whom I would express my thanks. Some thirty-two plaice, two soles, and twenty-five rays were placed in one of the big outdoor tanks for the experiments, and were all in good condition, though they had not been fed and were certainly overcrowded

The electric tattooing needle used was bought from a professional tattooist, who also gave me a brief lesson on his art. In principle the needle is a small vibrator run from an ordinary torch battery.