ie ie ee 
Marcu 28, 1912] 
NAT OFUE 
93 
the personal equation by the enumeration of the 
organisms, that makes biological work of this kind 
so valuable. Whatever errors creep into quantitative 
plankton studies—and no one knows better than the 
planktologist the inaccuracy of the methods—they 
occur in a similar way throughout, and affect all 
calculations to the same extent. The final result is a 
series of comparable observations, and the possibility 
of comparison is the keynote of quantitative plankton 
work. 
Hensen’s treatment of two of his critics does not 
seem quite fair. Kofoid’s objection that the original 
net lost many of the smallest organisms has been 
upheld by the work of Lohmann. As for Herdman’s 
work in the Irish Sea, the absence (which he has 
insisted on) of the uniform distribution of plankton 
necessary if observations made at stations far apart 
are to be of any value cannot be denied. Further- 
more, it is just in waters like the North Sea and 
Irish Sea that most naturalists find it possible to 
work. Whatever may be the cause of the com- 
plexities in the Irish Sea, the variations which have 
been followed by the Port Erin workers have been 
of such magnitude that no small errors could in- 
validate the deductions drawn. 
The influence of Hensen and his quantitative 
methods has been greater than at first sight would 
be imagined. There is no doubt that, as in many 
other cases, work along quite different lines has been 
stimulated or even created. Take, for example, the 
careful analyses of sea water, the study of the dis- 
tribution of nitrogen, of silica, and hydrographic 
work in general. There was a continuous demand 
for very accurate knowledge from those who would 
explain distribution by the altered environment. It 
was the plankton expedition itself that startled 
biologists with the statement that life was more 
abundant in the Arctic and temperate waters than 
in the tropics, and out of this has arisen the in- 
genious attempts to explain the anomaly. Bound up 
with this is the search for the factors which govern 
the seasonal changes in the plankton and the detailed 
researches which have been made on the latter in 
seas and lakes throughout the world. The question of 
the food supply of aquatic organisms, now no longer 
a simple subject, but one bristling with unsolved 
problems, requires further research along many 
different lines, particularly chemical and physiological. 
Finally, the systematist who follows the indi- 
vidual organisms, counting as they pass across the 
field of view, recognises the variations in shape and 
size, and hesitates before coining new _ species 
(especially if working through a year’s catches). In 
fact, for the study of evolution we need to go to 
the simplest organisms existing under the most simple 
conditions of environment. For this purpose there 
is a wide field open for research in the plankton of 
warm waters. Hensen shows that the seasonal 
variations, which complicate so much plankton studies 
in our waters, are to a great extent absent in the 
tropics. . It is probably the seasonal variations which 
are at the bottom of many strange features of dis- 
tribution round our islands. It would be quite impos- 
sible to touch on the numerous points of interest 
(many of which should create discussion) in a short 
article. Victor Hensen must be congratulated upon 
the conclusion of a work to which he has given so 
much of an active life. 
(2) Two other works which have recently been pub- 
lished may very conveniently be discussed here. The 
first deals entirely with those small organisms which 
pass through the finest tissue of which plankton nets 
are made. 
Lohmann has proved himself to be one of the fore- 
NO. 2213, VOL. 89] 
most plankton workers in the world, and it is to this 
man of science that we owe our knowledge of the 
limitations of Hensen’s methods. Thus the methods 
of the Kiel school have received their critical tests 
at the hands of the Kiel school. Lohmann proposes 
to use the term “nannoplankton”’ for the very small 
organisms, both animal and vegetable, of the pelagic 
world. 
At the present time Schiitt’s terms, macro-, meso-, 
and mikro-plankton, are usually employed. No exact 
definitions of these groups were ever given, but the 
macroplankton was understood to include such organ- 
isms as medusz, whilst the rest of the plankton in 
a net catch belonged to the groups, meso- and mikro- 
plankton. The former of these two divisions included 
the copepoda, worms, &c., and the protozoa and 
protophyta made up the second. To these three terms 
Lohmann adds two others: the ‘‘megaloplankton,” for 
all large organisms visible from a ship’s deck and 
varying in size from centimetres to metres, and the 
nannoplankton for the most minute forms. 
Naturally, different apparatus is required for the 
collection of the nannoplankton, and the net has been 
supplanted by the centrifuge. Water can be bottled 
at any depth, and it has been found that quite small 
quantities suffice. 
It must be remembered that though the actual 
volume of the nannoplankton is small, the degree of 
importance depends on the rapidity of multiplication 
and the duration of life of the organisms of this 
group, and in this respect their absence from the net 
catches of the plankton expedition is much to be 
deplored. 
(3) The other work to be mentioned differs entirely 
from the above in being a text-book, and there can 
be no doubt whatever that such a book is necessary 
to-day in consequence of the great extension of plank- 
ton work during the last few years. This volume 
gives a detailed and fair description of all the methods 
employed, with the results of recent researches in 
seas, lakes, and rivers. 
Its greatest value will be perhaps to those biologists 
and general scientific workers who wish to obtain 
information about this branch of biological science 
without wading through the vast number of small 
papers which have been already published. Prof. 
Steuer is to be congratulated on the very able way he 
has brought so many different lines of work together, 
and the volume ought to find a place waiting for it 
in most university libraries. W. J. Dain. 
UNIVERSITY REFORM IN NEW ZEALAND. 
T may be taken for granted that all universities 
are not built on the same pattern; that local 
conditions and the requirements of the population 
have to be taken into consideration. The American 
and German universities, with their plans of govern- 
ment and conditions of study, meet the requirements 
of the respective peoples; Oxford and Cambridge, with 
features in common with one another, differ widely 
from the rest of the British universities in many 
respects. The type of the Scotch universities is un- 
like that of the modern English institutions, such as 
Liverpool and Manchester, while that of London is 
organised in a fashion peculiar to itself. 
It is not to be wondered at, therefore, that the 
University of New Zealand should present anomalies 
ih its constitution; the peculiarly isolated position of 
the country, the great difficulties of communication 
between its chief towns, especially in early days; the 
paucity of university men both on the staffs of the 
colleges and outside their walls at the period of its 
foundation; the local prejudices, amounting almost to 
