On some Problems of the Distribution of 
Marine Animals. 
HEN Professor Hensen started on his Plankton expedition in 
1889, to attack the problem of the ‘‘ metabolism of the ocean”’ 
from a new point of view, and with methods other than had 
been employed hitherto, he wanted, as is well known, to study the 
organic life in high seas as free from the influence of coasts as possible, 
so as to obtain a more accurate conception of the distribution of 
animals and plants, and to procure a large quantity of material 
to which no exception could be taken from which to draw conclusions. 
Of course, he does not believe, as some of his opponents would have 
one think, that he has determined once and for all, by his captures, 
the contents of the part of the ocean he passed through; he merely 
intended to see what kind of material occurred at that particular 
time, and Hensen himself is well aware that such complicated 
problems as are resting in the bosom of the ocean can only be attacked, 
and not solved offnand. 
The hypothesis upon which he acted was, that the distribution of 
organic life, if not influenced by the coasts and the everchanging 
conditions we observe there, must be sufficiently constant to enable 
us to obtain an accurate idea of the contents of the ocean by fishing 
in more or less limited areas with the help of accurate nets. 
His views were already contested and defended at the time 
when the question of supplies for the expedition was being discussed, 
and there were naturalists who, without being quite convinced’ 
of Hensen’s views as to the uniformity of the marine fauna, were, 
nevertheless, strong upholders of his plans, saying that such an 
undertaking as his was worthy of support in any case, as the results, 
whatever they might be regarding the uniformity of ocean life, would 
certainly be a large contribution to our knowledge of biological and 
morphological questions. 
So far as I can ascertain from a relatively small part of the rich 
material which the expedition brought home (the Craspedote Meduse, 
which were given to me to work out), this view has, as a matter of 
fact, proved true. In the bottles entrusted to me, I was able to 
examine several new and interesting forms, besides many other 
species not sufficiently characterised at present, and the material, 
