33 
5. Thisted Bredning, 10.5 meters depth, 6. July—10. August 1910. 
In 1 detritus-collector 29.58 gm. 
per ”/,, m. 44.7 gm., per day 1.28 gm. 
6. Nissum Bredning, 26. September—29. October. 
In 1 detritus-collector 117 gm. 
per ”/,, m. 175.5 gm., per day 5.16 gm. 
Å microscopic examination of the material deposited in the detritus- 
collectors shows the same picture as has already twice been described, namely, 
under the description of the brown surface layer on the bottom in Thisted Bred- 
ning and under the description of the suspended matter centrifuged from the 
sea-water. 
The principal mass of the organic material deposited in the detritus- 
collectors consists, as in the two other cases, of detritus — a mixture of fine inorganic 
particles, only a small part of which can be diagnosed. 
A chemical investigation of the matter deposited in the detritus- 
collectors gave the following result. Detritus from Thisted Bredning contained 
2.59, carbon. It will be remembered that the uppermost, brown layer on the 
bottom of Thisted Bredning contained 3.06"/, carbon, thus almost the same result. 
Detritus from Nissum Bredning contained 1.79?/, carbon. The bottom-analysis 
from Nissum Bredning given in the preceding section contained only 0.356 "/, 
carbon; but this analyses did not refer, as in Thisted Bredning, to the upper- 
most layer alone. In that case it would certamly have given a somewhat 
higher value. It seems clear, therefore, both from the microscopice and 
the chemical investigation, that the material obtained in the detritus- 
collectors is completely identical with the uppermost brown layer on 
the sea-bottom. 
If we consider the data given above, which show the quantity of material 
deposited in the detritus-collectors per day, we see at once, that the numbers vary 
very greatly. In the period from 4. June—5. July 0.07 gm. is deposited per ”/1, 
m.? and day, whilst from 25. April—21. May 2.24 gm. are deposited daily, thus 
over 30 times as much. This confirms what we have already discussed under the 
determination of the organic matter suspended in the sea-water, that the wind 
plays a great part in the suspension and thus also in the precipitation of organic 
and inorganic matter in the sea. As will be remembered, June of 1910, in which 
so little material was deposited in the detritus-collectors, was on the whole remarkable 
for fine and calm weather. 
The origin of the matter deposited in the detritus-collector is certainly 
twofold; on the one hand, there is a constant transport, especially when the water 
is in motion, of inorganice and organic materials from the shore and the plant belt 
out into the sea, where they are deposited; on the other hand, the detritus, which 
has already been deposited on the bottom, is stirred up anew, certainly during 
strong winds, and then again deposited. This may obviously he repeated several 
times. The large quantity of detritus, which is deposited im the detritus-collectors, 
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