20 
the clay bottom, which all show, that the quantity of organic matter out there 
is fairly large, namely, about 2 /, carbon. 
Passing from the Kattegat into the fjords, there is much less movement in 
the water, and corresponding to this the clay particles and the organic material 
are deposited in much shallower depths. Here we must go into a depth of 2—3 
meters to find the sandy bottom. Already at a depth of 5 meters we meet with 
the strongly clayey soil, which composes the greater part of the bottom in our 
fjords and Bredninger, and from which the majority of the above-mentioned 
analyses originate. As will have been seen, we have at least the same amount of 
carbon as in the Kattegat at 35 meters depth. 
7. Origin of the organic matter on the sea-bottom. When we pass now 
to consider more closely, where the organic material of the sea-bottom comes from, 
whether it is the vegetation of the Zostera belt or the plankton orga- 
nisms which play the greatest role in this regard, we must first make sure, what 
the carbon analyses given above indicate and for what purpose they can be used. 
"As shown, we have determined the percentage quantity of carbon in the upper- 
most part of the bottom-soil in dry condition, and the numbers indicate 
therefore only the quantity of carbon or organic matter in relation to 
the inorganic material which exists in the bottom-soil. 
Owing to the relative value of these figures, we must therefore, to obtain 
results from them, proceed with very great caution. That one place of the sea- 
bottom shows more organic material than another, does not necessarily mean, 
that at the first place more organic matter is deposited annually. Possibly this 
is simply due to the fact, that relatively little inorganic matter is deposited at 
the first place, but a relatively large quantity at the other place. With this in 
mind we way now consider the analyses from the Limfjord. 
We may begin with a comparison of Louns Bredning with Livø Bred- 
ning. Louns Bredning belongs to the inner reaches of the Limfjord. Through 
Virksund it is connected with Hjarbæk Fjord and through Hvalpsund it opens out 
into Livø Bredning. Both Louns Bredning and Hjarbæk Fjord are very shallow. 
According to the Chart (see Beretn. f. Biol. Stat. VI, 1895, pg. 32) only a little 
over "/.rd of Louns Bredning lies outside the 6 meter line, and in Hjarbæk Fjord 
a depth of 6 meters only occurs at all in the channel which leads in through 
Virksund. We may therefore expect an extremely rich Zostera vegetation. On 
the Chart prepared by Ostenfeld to show the distribution of the Zostera in the 
Limfjord (cf. Ber. f. Biol. St. XVI, 1808, pg. 27), these Bredninger are unfor- 
tunately not included; but both from information received from Petersen as from 
personal observation I know that there is an extremely rich Zostera vegetation 
at these places. Hjarbæk Fjord in fact is even almost quite covered with Zostera. 
Livø Bredning on the other hand is considerably deeper and the shores 
are steeper. About ?/,rds of Livø Bredning lies outside the 6 meter line, accor- 
ding to the above Charts. Nor does the Zostera vegetation cover so much ground 
in Livø Bredning, as a glance at Ostenfeld's Chart will show. The largest 
growths are found in Draaby Vig on the east coast of Mors. 
With regard to the proportion of plankton in Louns and Livø Bredning, 
we have only a single estimate in the VIIth Report of the Biological Station for 
