6-7 EDWARD VII. 



SESSIONAL PAPER No. 22a 



A. 1907 



I 



THI^] PLANKTON OF EASTERN NOVA SCOTIA WATERS. 



AN ACCOUNT OF FLOATING ORGANISMS UPON WHICH YOUNG FOOD- 

 FISHES MAINLY SUBSIST. 



By R. Ramsay Wright, M.A., LL.D., &c., 

 Professor of Biology and Vice-President University of Toronto, 

 (with seven plates.) 



INTRODUCTION. 



Within recent years much attention has been given to the floating microscopic 

 organisms which abound in all great bodies of water — fresh and salt. It had not been 

 sufficiently realized until it was insisted upon by Haeckel, Hensen, Brandt and others, 

 that our attention has hitherto been arrested chiefly by the animal life of the sea and 

 the great lakes to the neglect of the vegetable food-supply which necessarily forms the 

 conditio sine qua non for the existence of all animal life. On land the vegetable king- 

 dom everywhere seems to be predominant, and to account amply for all the animal life 

 which feeds on it directly or indirectly. But in the ocean, the obvious plants — the sea- 

 weeds, brown, green and red — form a mere inconspicuous fringe of vegetation along 

 the shore, and do not extend out beyond a few fathoms in depth. Such a fringe of 

 vegetation can practically be neglected as the basic food-supply of the animal life of 

 the ocean, and the question comes to be, ^ Whence do marine animals derive their fun- 

 damental supply of nourishment ? ' Living creatures are either builders or destroyers 

 of protoplasm, or in familiar parlance, either plants or animals, and the former are^ 

 necessary to sustain the life of the latter. In what form then do these necessary pro- 

 toplasm builders exist in the sea and other great bodies of water ? 



The answer is, in the form of microscopic plants, often quite invisible to the naked 

 -eye and yet present in such enormous numbers, not only at the surface but through the 

 whole of the superficial layers of waters, some sixty fathoms deep (as far as the sun- 

 light reaches, on the presence of which their power to build protoplasm depends) that it 

 has been calculated that an acre of sea-water — surface measurement — furnishes as 

 much nutritive vegetable matter as does an acre of rich meadow land in the course of 

 a year. 



No one sailing over the Atlantic suspects the presence of such a rich vegetation, 

 and indeed it can only be disclosed by filtering the water through an exceedingly fine 

 fabric — the finest silk gauze used by millers is that generally employed for the purpose 

 — and this is usually done by towing a net of such a fabric behind a boat so as to in- 

 sure a definite amount of water passing through it. 



Investigations made in this way may be either qualitative — merely to determine 

 the nature and relative numbers of the organisms so captured — or quantitative — to 

 determine the absolute amount of the different kinds of organisms in a column of 

 water of given dimensions. 



It is such quantitative investigations which have rendered the statements as to 

 the richness of the marine vegetation possible, which are made in the foregoing 

 paragraph. 



The tiny organisms obtained in this way are not all plants, many of them are 

 animals, feeding on the former, and themselves serving as food for larger creatures. 



