Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/60

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annually increasing. Many of them publish Proceedings of considerable merit ; and others tend, by field-work, to spread a taste for your science.

Deep-sea Life and its Relations to Geology.

Among the collateral subjects which have engaged much attention during the past year, and which must exercise a considerable influence on future geological speculation, is that relating to the nature of the sea-bed, the temperature of the sea at great depths, and the range and distribution of animal life in those depths — investigations which have been so greatly promoted by the recent expeditions of H. M. surveying-steamers ' Lightning ' and ' Porcupine.' Subjects of this nature have always been of much importance to the geologist, who has therefore ever followed with the keenest interest the researches of the naturalist and physicist. In studying the marine Invertebrata the early naturalists were long limited in their observations to the shore-line, and to such moderate depths as were within reach of the ordinary fishermen or their own small appliances. Now and then a deep-sea sounding would give a fragmentary insight into other zones of depth; but from their exceptional character they did not attract much notice. Lamarck, 0. F. Muller, Montagu, Poli, and Risso furnished some facts relating to depth as well as to geographical distribution ; but still, when we look to the short table by Mr. Broderip of the " Situations and Depths at which recent Genera of Marine and Estuary Shells have been observed," appended to Sir Henry de la Beche's ' Theoretical Geology,' it shows bow scanty our information was so late as the year 1834. No Mollusca are there given from a depth greater than 420 feet, and no Brachiopoda from one greater than 540 feet.

In the various inquiries which engaged the attention of the eminent men who formed part of the many Arctic expeditions, that of the distribution of life in the sea was not lost sight of, although, from the imperfection of the means, the results were very scanty. The small quantity of mud or stones attached to the sounding- apparatus, or brought up by the deep-sea clam, furnished, in fact, all the glimpses they were able to obtain of the ocean-bottom. Although the specimens were often crushed and broken, still the evidence, so far as it went, was in many cases clear and definite.

Sir John Ross records, in his voyage to Baffin's Bay in 1817— 18, three deep-sea soundings. In the first, at a depth of 2700 ft. *,

  • I have in all cases expressed the sea-depth in feet instead of in fathoms,

in order to conform with the terms applied to elevations on the surface and dimensions of strata.