5 
population of plaice«, which alone was the cause of the slow growth there. 
This probably comes near io the kernel of the matter also, but there are perhaps 
other moments in addition. My first idea at that time was, that the slow growth 
might be due to the fact, that the bottom in the western parts out towards the 
North Sea was not so rich in food-animals as in the inner reaches; from this a 
new problem arose: how could we compare the quantity of the bottom- 
fauna at one place with the quantity at another? 
In 1896, again with the help of the gunboat »Hauch«, I endeavoured to 
fish up all the animals on the bottom within a space of 0.1 m”. by means of a 
somewhat primitive apparatus. The apparatus was fixed at the end of a long 
pole, long enough to reach the bottom in these shallow waters, which are only 
ca. 6—12 meters deep. AÅA number of samples were counted, but the results have 
never been published. My impression, and also that of Dr. Th. Mortensen who 
assisted me at that time, was that there were almost as many animals in the 
western regions as in the inner fjord per m?, and that the slow growth of the 
plaice in the west must therefore be explained from the principle of overerowding. 
I shall return later to this question and only mention it here, because I believe, 
that it was the first time an actual counting of the animal life on the bottom 
per m? was made, apart from a few attempts to count the quantity of the animals 
near the shore at ebb-tide. 
It was in 1908 that I returned again to these investigations, as I now had 
a special steamer at my disposal and could carry them out better and in addition 
had found through numerous experiments a better apparatus, which could fish up 
the animals on 0.1 m? even at considerable depths and without the pole. This 
apparatus, the »0.1 m? bottom-sampler« has been much used during the 3 years 
1908—9—10 and at many places in our waters; with its help we can quickly 
investigate whether a water is rich or poor in this or that kind of food, a matter 
that is of special importance with us, where the question of the inplanting of 
plaice and flounder has become actual. Such an investigation is not possible 
with the dredge; I have seen how incorrect are the pictures we may obtain 
regarding the richness of the bottom from the use of the dredge. Å certain 
comparison between two waters can certainly be obtained from the dredge, but 
this is not always sufficient, and it is especially impossible in this way to obtain 
a true measure of the quantity of food present, and as time went on I felt this 
to be more and more a necessity. It has now been proved over a number of 
years, that the transplantation of young plaice to the central parts of the Limfjord 
is a very profitable undertaking, even when only 40 or 60 plaice are transplanted 
per hectare, and the question thus arose, how many can be inplanted per 
hectare before their growth becomes slow. In addition to being able to judge 
this matter simply by making a kind of artificial overcrowding, it would also be 
desirable, if we could estimate by some other way, by investigation of the quan- 
tity of the animals available as food, whether we were near or far from this 
danger-point. 
The new bottom-sampler soon showed, that some of our waters are 
rich in animals which serve as food for the plaice, others poor, even 
exceedingly poor, and this was often accompanied by a different appear- 
