PLANKTONIC STUDIES. 629 
day” (23, p. 516). Meanwhile Brandt, explaining the “highly original 
procedure” of Hensen (‘turning attention to attacking a problem, the 
solution of which no one had ever thought of”), remarks, with refer- 
ence to the foregoing quantitative analysis of the Atlantic plankton 
expedition of the National (1889), “that the very much more manifold 
ocean catches will consume presumably twice as much time, and since 
on the plankton voyage at least 120 such catches were made, then the 
working out of these (quite apart from the preliminary preparations) 
will fully oceupy an investigator for 120 x 14 days, or about 6 years” 
(23, p. 516).* 
Opinions respecting the significance and the value of the oceanic 
population statistics of Hensen are very different. KE. du Bois-Rey- 
mond, in his paper before the Berlin Academy (21, p. 83),t attributes 
to it extraordinary importance, “wherefore the uncommon sacrifice 
made for it was justified.” According to his opinion, the plankton 
expedition of the National, arranged for this purpose, within its defi- 
nite limits, from the novelty and beauty of its well-described task, 
assumes a unique place, and the Humboldt fund ought to be proud at 
having been among the first to contribute to its execution” (21, p. 87). 
On the ground of this honorable recognition, as well as of the great 
hopes which the naturalist of Kiel himself based upon the results of 
the National expedition, numerous notices have appeared in German 
newspapers, disseminating the view that an entirely new field of 
scientific investigation had been thereby actually entered upon, and 
that a further extension of it was of great importance. I am sorry to 
say that I can not agree with this very favorable conception. 
DISTRIBUTION OF THE PLANKTON. 
The foundation upon whieh the entire planktonic conception and 
computation of Hensen rests is the view “that in the ocean the plank- 
ton must be regularly distributed; that from a few catches very safe 
estimates can be made upon the condition of very great areas of the 
sea” (22, p. 243). As Hensen himself says, he started with this “purely 
theoretical view,” and he believes that a completely successful result is 
to be had, because these theoretical premises have been more fully 
*According to this, the unfortunate plankton counter would in these 120 catches 
have to count for over 17,000 hours. How such an arithmetical Danaidz work can 
be carried through without ruin of mind and body I can not conceive. 
tIn the introduction to this noteworthy paper Du Bois-Reymond says that since 
1882 Hensen “had been mindful that, especially on the surface of the sea, there was 
found a more wnequally numerous population of minutest living forms than had 
previously been supposed” (21, p. 83). This remark needs correction, because many 
times in the celebrated log book of the National plankton expedition this has been 
overlooked, and therefore it has wrongly been inferred that Hensen eight years ago 
was the first to discover the existence and abundance of the pelagic fauna and flora, In 
fact, for forty-five years they have been the object of wonder and study for numerous 
naturalists. 
