. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. DISTRIBUTION OF PHYTOPLANKTON and January, and giving place to other species of Coscinodiscus and to Corethron val- diviae. It was all but absent in the five Sts. WS i io-i 14 taken in autumn, late May, on the C line; 400 (4) only being taken at St. WS no. Our survey of December and January appears to show Coscinodiscus bouvet in the act of declining and sinking. The majority of them appear to die. It is interesting to speculate whether some of them remain alive, perhaps forming resting spores,
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. DISTRIBUTION OF PHYTOPLANKTON and January, and giving place to other species of Coscinodiscus and to Corethron val- diviae. It was all but absent in the five Sts. WS i io-i 14 taken in autumn, late May, on the C line; 400 (4) only being taken at St. WS no. Our survey of December and January appears to show Coscinodiscus bouvet in the act of declining and sinking. The majority of them appear to die. It is interesting to speculate whether some of them remain alive, perhaps forming resting spores, and sink from the surface layers of water, which are moving northward, into the lower masses of water moving back towards the pole. This might explain how species can maintain their population in the south when I o< ? 10,000-30,000 rR :T%^f-^- B 3. E B " 3 3 U JO' *0° *y 39' JO' 38° JO' 37° JO' 36" JO' Fig. 16. Distribution of Coscinodiscus bouvet round South Georgia in the December-January 1926-7 survey. Scale of squares represents numbers per haul with N 50 V net from 100 m. to the surface. (See section on significance of plankton numbers, p. 40.) Negative observations shown as dots. The dotted lines BB and WW mark the probable boundaries of the surface waters from the Bellingshausen and Weddell Seas re- spectively, the zone in between being an area of mixing (cf. Fig. 6). they are continually being carried away from the pole in the surface layers. No such spores were seen, but a few cells were found to be living even below 1000 m. All those that were found in the top 100 m. appeared to possess chromatophores; but below this level the percentage of those containing chromatophores decreased as the depth. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Institute of Oceanographic Scienc
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