The symbiotic condition of Convoluta roscoffensis has been resynthesized in vitro by feeding new-born colourless larvae with various clones of Platymonas convolutae Parke & Manton available in culture. Greening has also been brought about by feeding larvae with other species distinguishable from the natural symbiont by pyrenoid characters, but subsequent growth of the greened larvae was less and the length of time required for greening greater. The minimum presentation time effective in initiating greening with alien symbionts in 100% of tested larvae was also greater. Cell multiplication of successful symbionts is mitotic, division stages being demonstrated in sections of worms with different types of symbiont. When cultures of potential symbionts were made available competitively in pairs, greening normally involved only one member of a pair, success being apparently determined by the order of relative efficiency demonstrated in the single-culture infections. A chimaeral condition, with two different symbionts present together, was produced and is demonstrated—but only as a temporary phase in an experiment designed to give an alien symbiont a very long start before admitting the real one. In this experiment effective greening with Prasinocladus marinas did not impede prompt entry of Platymonas convolutae when it was supplied, and this was followed by rapid and complete elimination of the alien symbiont. An interpretation of these various findings is discussed in a preliminary way.

The ‘detergent’ BP 1002 at concentrations of 1 ppm was detected immediately by the larvae of Sabellaria spinulosa which were intensely irritated by it. In loosely covered vessels, allowing the solvent fraction to evaporate, larvae seemed at first to recover but died several weeks later, the control larvae remaining active and normal. The surfactant and stabilizer fractions at concentrations of 2·5 ppm killed the larvae within a day or two.

Sand was soaked for 90 min in sea water containing the ‘detergent’ BP 1002 in concentrations of 1000 and 100 ppm (= mg/1.) and then thoroughly washed. Larvae crawling on it soon afterwards were damaged, but the toxic effect disappeared after some days.

From 1964 to 1967, 163 deep-sea fish have been caught from 28 line hauls in depths of from 1000 to 3300 m. Slightly over half the total catch consisted of elasmobranchs. The largest individual fish was a shark Pseudotriakis microdon of 2·25 m length taken from 1400 m. The distribution of the eleven species taken regularly in these and previous hauls is compared and contrasted.

At the junction between the scyphistoma's scyphopharynx-filament complex and its endoderm is a narrow zone of simple columnar cells. These cells can transform into amoebocytes which collect together and work their way to the aboral end of the polyp, where they secrete a cuticular encasement, thus forming the podocyst.

Light and electron microscopy, as well as histochemistry, show the podocyst to be a lamellated tanned chitin-protein complex covering the protoplasmic contents, which have a nucleated outer clear cytoplasmic layer and a yolky central zone which may be liquefied in places.

A modified volumetric respirometer was constructed for an extended series of precise determinations of the respiration of small aquatic animals. Food could be introduced and all operations could be carried out without disturbance to the animal. Provisions were made for the introduction of filtered, bacteria-free sea water between experimental runs. The advantages of the volumetric technique were combined with those of a running-water system to allow the continuous measurement of oxygen consumption under controlled conditions.

In 1962, 1964 and 1966 the author collected four species of marine triclads, viz. Procerodes littoralis (Ström), P. ireneae sp.nov., P. lobata (O. Schmidt) and Uteriporus vulgaris Bergendal in the Plymouth neighbourhood. Each species is fully described. Attention has been given not only to internal characters, as the structure of the genital apparatus, but also to external features such as the shape of the head and the pattern of pigmentation, because these external characters are sufficient for the identification of the species. Further, the geographical distribution and ecological data have been recorded for each species.

A study of nineteen species of monotocardian veligers belonging to eight different superfamilies reveals the uniformity of structure of the alimentary tract up to the time of metamorphosis. Results of feeding experiments with nineteen species of unicellular algae show that there is also uniformity in the functioning of the gut.

The fatty-acid compositions of tissue lipids of Asterias rubens L., Echinus esculentus L. and Holothuria forskali Delia Chiaje were determined by means of gas-liquid chromatography. Considerable proportions of branched-chain, normal odd-numbered and eicosatetraenoic acids occur in the latter two animals. Tissues of all three animals were incubated with 1−14C-acetate. The relative specific activities of fatty-acid fractions isolated by thin-layer chromatography upon AgNO3-impregnated silica gel G fell in the order: saturates > monoenes — dienes > polyenes. The fatty-acid compositions of the alkoxydiglyceride, triglyceride and phospholipid classes of A. rubens hepatic caecal lipid were also determined.

The population of Scoloplos armiger O. F. Müller at Whitstable was investigated from January 1964 to April 1965. Initially the population density was high, being over 600/m2, but the numbers sharply declined during the summer of 1964 and by the following winter the density had dropped to under 100/m.2 In addition to this decline, the population structure changed, and the overall effect was a marked reduction in the fecundity of the population. The cause of the high mortality in the summer of 1964 is unknown.

The effect of temperature on the rate of reaction catalysed by crude muscle AMP-aminohydrolase from two species of elasmobranch and two species of teleost fish has been investigated at low substrate concentration in the range of temperature 5–50 °C.

The enzyme from teleost fish shows a very broad temperature optimum around 30 °C. The reaction rate of the enzyme from elasmobranch fish is strongly dependent on temperature. The optimum temperature for the enzyme from thornback ray lies around 40 °C. Both crude and 500-fold purified AMP-aminohydrolase from thornback ray show the same temperature-dependence.

Bioluminescence has been observed in 11 halocyprid ostracod species, and the sites of secretion are described.

Bioluminescence in cypridinid ostracods has been thoroughly investigated (Harvey, 1952). However, since the original suggestion that the edge glands in the carapace of halocyprid ostracods secrete luminescent substances (Claus, 1891), only a single observation has been made confirming this suggestion on Conchoecia curta ( =clausi) (Müller, 1894).

The origins of the Marine Biological Station go back to 1885, when Professor, later Sir William, Herdman organized the Liverpool Marine Biological Committee. The Committee conducted dredging excursions in the Irish Sea, and also set up a very small shore laboratory on Puffin Island (off Anglesey) from 1887 to 1891. In 1892 activities were transferred to two small stone buildings (which still exist—see Pl. III) on Port Erin Bay. After nine years these buildings had become quite inadequate to accommodate the growing numbers both of visiting naturalists and of vacation classes which were started at Port Erin in 1897, so a further move was made to the present site at the south-west corner of Port Erin Bay in 1902.

In 1919 the control and ownership of the Marine Biological Station was transferred from the L.M.B.C. to the University of Liverpool; until 1939 the Station formed part of the Department of Oceanography, from 1939 to 1949 it was part of the Department of Zoology, and since 1950 it has formed a separate Department of the University.

The original building of 1902, whose whole seaward frontage still remains virtually unaltered (Pl. I), consisted of a central public aquarium (now room 5 on Text-fig. 1) flanked by a sea-fish hatchery (now 8, 9) and a few small research rooms (2,3,4,6,7), with two sizeable laboratories for student classes on the first floor (45–47 and 28, 30–32 on Text-fig. 2). A very valuable asset consisted of three large open-air ponds which still, after 65 years, perform their original function of maintaining a breeding stock of some 200 adult plaice.