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THE DEPOSITS OF THE SEA-BOTTOM. 



Section IV. 

 The Organic Ingredients of the Bottom-Specimens. 



In the preceding sections we have only paid regard to the mineral ingredients, and have tried 

 to get a clear view of their distribution; but the examination of the bottom-specimens is not finished; 

 the organisms make so prominent an element in most of them, that they require a special examination. 

 Of course the question cannot here be of a determination of the individual genera or species; that 

 would require the labour of many specialists; the essential thing will here be to point out the part played 

 by the individual groups with regard to the constitution of the specimens, and to find, if possible, a 

 connection between the locality and other circumstances of the specimen on one hand, and the leading 

 features with regard to its organic contents on the other. Most frequently the part of the organisms 

 found in the specimens, is their shells or skeletal parts of lime or silica; the organic substance has 

 almost always completely disappeared; nor have ingredients of horn or bone been found with the ex- 

 ception, perhaps, of a single jaw of an Annelid. In some of the specimens, on the other hand, sand- 

 tubes are found belonging to some of the larger Foraminifera. The only specimens, in which organic 

 substance has been found, are the three northermost ones at the western coast of Greenland, nos. 31 

 —33; here are found pieces of Algae, partly larger fucaceae, partly smaller, tubular ones, and partly 

 microscopic threads of Algae. The tubular Algae were in a curious manner intervowen with grains 

 of sand and sponge spicules placed transversally to the longitudinal direction of the tube. 



The distribution of the organic ingredients must be essentially another than that of the 

 minerals, and at the same time more implicated. While the mineral ingredients of each single speci- 

 men may, as a rule, be pointed out to have been transported from a certain, larger or smaller, terri- 

 tory, a corresponding supposition will in no way hold good with regard to the organisms; those 

 found in an individual specimen, may have lived on the same locality, and have sunk to the place, 

 but they may also have lived in every possible, though not too large, distance from the specimen, 

 and in every possible direction, and have been transported by currents, as to the nature of which it 

 is impossible to come to any conclusion. A closer zoological and botanical examination will perhaps 

 give some elucidation with regard to this; if we shall be able to point out species living in some 

 limited region of the surface of the sea, we shall also be able to draw inferences with regard to the 

 currents from the distribution of those species in the bottom-specimens; such inferences, however, will 

 never be very reliable, if they are not founded on examinations from a greater series of years, as at 

 least many organisms are very differently distributed from one year to another. With regard to the 

 organisms living on the bottom of the sea, the question, of course, will be less intricate; there is no 



