The work reported in this paper forms part of a programme of investigation into the normal parameters of radiosensitive tissues in the plaice. The work was conducted prior to investigations into the effectsof ionizing radiations on these tissues, in order to form a backgroundto examinations of fish from areas of radioactive pollution resulting from the controlled disposal of radioactive effluent. Tissues were selected on the basis of known radiosensitive tissues in mammals and the work on red blood values reported here arose from these preliminary investigations.

Many free-living and parasitic invertebrates have been known to tolerate low oxygen tensions and anaerobic conditions. Von Brand (1946) who reviewed the extensive literature on anaerobiosis in invertebrates listed species of Cyclops which under experimental conditions could tolerate 2–18 h of anaerobiosis. Apart from this, few experimental studies have been made on anaerobiosis in copepods, especially the parasitic species. Availability of a number of live Caligus diaphanus at Plymouth made it possible to make a few preliminary observations on the behaviour of this copepod parasite under anaerobic conditions.

The colour of the chromoplasts in the Chrysophyceae varies from a greenish yellow to a golden brown. Klebs (1892) described this colour as being due to a special pigment which he called ‘chrysochrom’. Gaidukov (1900) made an acetone extract of a dense bloom of Chromulina rosanoffii (Woronin, 1880) Biitschli filtered from the tanks in the cold glasshouses of the Botanic Gardens in St Petersburg. He found a water soluble pigment which he called ‘phycochrysin’ together with ‘chrysochlorophyll’ and ‘chrysoxanthophyll’. Most authors have since questioned the existence of special pigments in the Chrysophyceae (Fritsch, 1937; Smith, 1938). Carter, Heilbron & Lythgoe (1939) analysed extracts of an incrustation of Apistonema carteri, Thallochrysis litoralis and Gleochrysis maritima (identified by F. E. Fritsch) found on the chalk cliffs at Folkestone, and identified β-carotene, fucoxanthin and lutein, using calcium carbonate as adsorbent in their analysis. Heilbron (1942) later drew attention to the fact that these pigments are present in the Bacillariophyceae but not in the Xanthophyceae, throwing doubt on Pascher's view of the close relationship of all three groups. We now know that it is not lutein but diadinoxanthin that is present in the Bacillariophyceae (Strain, Manning & Hardin, 1944). Seybold, Egle & Hülsbruch (1941) then showed that the chlorophyll present in Hydrurus foetidus and Chromulina rosanoffii was chlorophyll a, apparently without other chlorophylls. Seybold (1941) has commented further on the singular occurrence. and implications of chlorophyll a alone, and this has been recently discussed by Allen (1958). In recent years our knowledge of the pigments of the algae has been greatly advanced by Strain and his colleagues (Strain, 1958) but, while the pigments of the Xanthophyceae and Bacillariophyceae have been examined with the improved techniques now available(Pace, 1941; Strain, Manning & Hardin, 1943, 1944; Strain, 1958), those of the Chrysophyceae have not.

The Association was greatly honoured on 18 March 1960 by a visit to the Plymouth laboratory of our Patron, H.R.H. The Duke of Edinburgh. His Royal Highness spent over an hour in the laboratory and aquarium, and met members of the staff and visiting research workers. The President and Honorary Treasurer were present for the occasion.

The Council have to report with regret the death of Dr W. R. G. Atkins, C.B.E., F.R.S., who was Head of the Department of General Physiology at the Plymouth laboratory from 1921 to 1955. During these years Dr Atkins laid the foundations of much of our present knowledge of the chemistry and physics of the sea and brought international renown to the Plymouth laboratory.