22 
of Zostera, is covered as mentioned above with a meter-thick layer of black, stink- 
ing mud with an amount of carbon of no less than 10,2/,. The”same is the 
case, though to somewhat less extent, with Bramsnæsvig and Holbæk Fjord. 
Information regarding the quantity of Zostera in the last-mentioned is given by 
the Chart in the I. Report of the Danish Biol. Station. On the other hand, as 
soon as we come out into the broad reaches of Isefjord, where the Zostera 
decreases, the quantity of carbon in the bottom-soil also decreases. It declines 
10R237R 0/0: 
In the Kattegat, as shown above, the Zostera is of far less importance than 
in our fjords, and we might perhaps be surprised that the two bottom-samples 
from the Kattegat, the one from Anholt, the other W.N. W. from Kullen, both 
contained over 2 ?/, of carbon. This is explained by the fact, that the portion 
of the Kattegat, which is sufficiently deep to permit of a deposition of 
organic matter, constitutes a fairly small part of the whole area of 
the Kattegat. A large part of the Kattegat is fairly clean sand, a still larger 
part a mixture of clay and sand. Of these the sand bottom only contains quite 
inappreciable quantities of organic matter (according to the analyses from the 
North Sea; we have no aualyses from the sand bottom in the Kattegat). It is 
only when we come out to a depth of over 30 meters that we find the deposits 
of blue clay, and it was from this soil that the analysed bottom-samples were 
taken. As Chart IM in the atlas of »Hauchs Togter« shows, this kind of soil is 
of very small extent, so that the material produced in the Kattegat is 
concentrated on a relatively small area; on the other hand, the percentage 
of carbon must be fairly high. Further, there is perhaps a by no means incon- 
siderable transport of Zostera from the Belt Sea. In any case large masses of 
seaweed are often met with floating in the Belts and the Kattegat. 
We may now pass from the home waters to a consideration of the bottom 
analyses from the Ingolf Expedition. Common to all the bottom-samples 
examined, with exception of that from Station 101, is that they contain extre- 
mely little carbon in comparison with the bottom-samples from the Danish 
waters. This agrees perfectly with the above-quoted statement of Murray and it 
harmonizes well with the idea, that the source of the organic material in the 
sea is mainly the plant-formations bound to the coasts, the algae and Zostera. 
We may notice further, that it is the bottom-samples which come 
from nearest the coast which contain most carbon. This is shown by 
the bottom samples from Stations 45—48, which lie in a line running towards the 
west from the Færoes. 
Station 45, which lies nearest the land, contains the largest quantity of 
carbon. It is even more distinct, however, in the determinations from the stations 
north of Iceland. The station nearest Iceland, 101, contains fairly considerable 
quantities of carbon namely 1.64 %/,, whilst Station 112, which lies furthest away 
from land, only shows 0.42 ?/,. This difference becomes even more obvious 
when we consider, that the largest quantity of inorganic material is 
undoubtedly deposited in under the land. Since, nevertheless, the percen- 
tage of carbon is much greater there, this can only mean thåt in under the land 
more organic matter is annually deposited than out in deep water, in other 
