REFERENCES z8 9 



On the second survey one intense red discoloration was seen close inshore in the extreme north 

 of the area, which was found to be due to the ciliate Cyclotrichiam meumeri Powers ( = Mesodinium 

 rubrum Lohmann) and its associated symbiotic alga. This is discussed in relation to previous observa- 

 tions of it round Cape Province, and recent revisions of the taxonomy. 



A rearrangement of the data concerning the main diatom groups, based on arbitrarily selected 

 distance limits, illustrates the distinction between offshore and inshore diatom floras, and provides 

 some basis for ecological characterization of the species within each of the groups, somewhat on 



Gran's lines. 



This concept is carried a stage further in an attempt at ' ecological characterization ' of the more 

 important plankton diatom species of the area. Comparison with their recorded distribution elsewhere 

 shows that they are even more cosmopolitan than was generally recognized hitherto. This lends point 

 to the argument that it is the relative importance of the various forms, rather than their mere presence 

 and absence, that must be studied before the relations between marine plankton floras and their 

 'conditions of existence' begin to be perceptible. In this there seems to be a basic contrast between 

 the planktonic floras and faunas, for 'presence or absence' is often of real significance in the latter. 



The zooplankton has been completely sorted only from survey I. Some groups have been reported 

 on and the findings of these are summarized. The outstanding feature of the zooplankton distribution 

 appeared to be its greater independence of specific water masses than the phytoplankton and a con- 

 spicuous patchiness in the distribution of some species. 



A brief account is given of other life in the current— notably the fish, seals and whales, and also the 

 guano islands, all of which are outstanding economic features of the region. 



Reference is made to a spawning ground of the South African pilchard, located between Walvis 

 Bay and Sylvia Hill. This is a point of some importance but has been dealt with in a separate 

 publication. 



Many features of the Benguela current are similar or analogous to those of other upwelling regions 

 and a concluding section is devoted to comparing the main features of the four major upwelling 

 regions of the world. The extraordinary richness of upwelling regions in comparison with the adjacent 

 oceanic waters presents interesting material for speculation on the process of organic production in 

 these environments. At present, however, our knowledge of the magnitude of the processes does not 

 permit any quantitative treatment of this problem. 



REFERENCES 



Aikawa, H., 1936. On the diatom communities in the waters surrounding Japan. Rec. Oceanogr. Wks. Jap. vol. vin, no. 1, 



pp. 1-159, figs. 1-60, tables 1-61. 

 Alexander, J. E., 1838. An expedition of discovery into the interior of Africa, vol. 11, 306 pp. London. 

 Allee, W. C. and Oesting, R., 1934. Winkler's method in the study of the respiration of animals. Physiol. Zool. vol. vn, 



pp. 509-41. 

 Allen, W. E., 1938. The Templeton Crocker expedition to the Gulf of California in 1935— the Phytoplankton. Trans. Amer. 



Micr. Soc. vol. lvii, no. 4. 

 Alsterberg, G., 1926. Die Winklerische Bestimmungs methode fiir in Wasser gelbsten elementaren Saurestoff sowie ihre Anwen- 



dung bei Anwesenheit oxydierbarer Substansen. Biochem. Z. vol. CLXX, p. 30. 

 Andersson, C. J., 1858. Reisen in Sudwest Afrika bis zum See Ngami in den Jahren 1850-54, vol. I, 288 pp. Leipzig. 



1861. The Okavango river: a narrative of travel, exploration and adventure, 364 pp. Hurst and Blackett, London. 



1866. Lake Ngami, 536 pp. Hurst and Blackett, London. 



Anon., 1874. Concerning the wind and upwelling off Kapstadt. Petermanns geogr. Mitt. vol. xx, p. 294. 



1926. Massenvernichtung von nutzfischen an der Sudwestkuste Afrikas. Mitt, dtsch. SeefischVer. vol. xlii, pp. 24-5. 



1951a. Sea eruptions off S.W. Africa. Bulawayo Chronicle, N. Rhodesia. 16th Feb., 1951 



19516. Three mud islands appear near Walvis Bay. Johannesburg Star, S. Africa. 6th Mar., 1951 



