bluuebunny/crossref_metadata_2025_split 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

SUMMARYFurther 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

SUMMARYThe 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

SUMMARYIt 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
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: 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.
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.
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.
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.
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 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 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.
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.