PLANKTONIC STUDIES. . 571 
| the Canary island Lanzarote. I also entirely agree with Chun in 
_ regard to his general views upon the chorology of the plankton, and 
consider his investigations upon the pelagic animal world and its rela- 
tion to the surface fauna as the most important contribution -which 
planktology has received since the pioneer discoveries of the Challenger 
and of the Vettor Pisani. 
Entirely new aspects and methods have been introduced into pelagic 
biology in the last three years by Dr. Victor Hensen, professor of phy- 
siology at Kiel (9 and 22). He has for a number of years thoroughly 
studied the conditions of life of the fauna and flora of the bay of 
Kiel, and as a member of the commission for the scientific investigation 
of the German Ocean (at Kiel) has endeavored to improve and extend 
the fisheries there, and by counting the fish eggs collected to get an 
approximate idea of the number of fish in corresponding districts (9, 
p. 2). This investigation led him to the conclusion that it was neces- 
sary and possible to come nearer to the fundamental food supply of 
marine animals and to determine this quantitatively. For solving this 
problem Hensen invented a new mathematical method (2, p. 33). He 
constructed a new pelagic net (p. 3), and in July, 1884, in company 
with three other naturalists of Kiel, undertook a nine-day excursion in 
the North Sea and Atlantic Ocean, which was extended to the Hebrides 
and to the Gulf Stream (57° 42’ N. Lat.) (p. 30). In 1887 he published 
the results of this investigation in a comprehensive work containing 
many long numerical tables, “On the Determination of the Plankton, 
or the Animal and Vegetable Material found in the sea” (9). He used 
the term “plankton” in place of “Auwftrieb,” the word hitherto com- 
monly used, because this name is not sufficiently comprehensive and 
suitable (9, p. 1). To be sure, the German term “Auftrieb” or “pelagi- 
scher Mulder,” introduced by Johannes Miiller forty years ago, was in 
general use and has many times been used in English, French, and 
Italian works. But I agree with Hensen that in this, as in other 
scientific terms, a Greek terminus technicus, capable of easier flexion, 
is preferable. I adopt the term Plankton in place of ‘“‘Auftrieb,” and 
form from it the adjective planktonic (planktonisch). The waole science 
which treats of this important division of biology is briefly called 
planktology. 
Hensen regards the mathematical determination of the plankton as 
the chief aim of planktology from a physiological standpoint. By it he 
hopes to solve the somewhat neglected question of the cycle of matter 
in the sea. For the purpose of solving this, and to make a trial of his 
new method on a larger scale, Hensen, in the summer of 1889, arranged 
a more extensive expedition in the Atlantic, which was most liberally 
supported by the German government and by the Berlin Academy 
of Sciences. The German Emperor furnished 70,000 marks; the Berlin 
. 
