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of Ireland, Mr. J. Gwyn Jeffreys diedgeJ up to a depth of fourteen hundred 

 and seventy-six fathoms. In the second cruise to the northern part of the Bay 

 of Biscay, Professor "S\'"yville Thompson dredged at the enormous depth of two 

 thousand four hundred and thirty-five fathoms, or more than 22 miles. In the 

 third, Dr. Carpenter again explored the sea bed between the north of Scotland 

 and the Faroe Islands at depths varying from one hundred to seven hundred and 

 sixty-seven fathoms. 



Tlie following important additions to our knowledge have resulted from 

 these explorations. Pii-st, as to Temperature. Only two years ago the accepted 

 belief was that the temperature of the sea at great depths was every^vhere con- 

 stant at 39.° The only reason for this belief seems to have been that fresh 

 ■water attains its greatest density at 39° and the same was assumed of salt water, 

 whereas the latter increases in density down to its freezing point at or below 28°. 



Between the north of Scotland and the Faroe Islands a cold area was 

 found, where over a considerable extent the temperature at a depth of three 

 hundred fathoms and upwards was below the freezing point of fresh water. At 

 one place, at six hundred and forty fathoms, the greatest depth found in the 

 cold area, the temperature was 29 '6, while at a similar depth at no great distance 

 the temperature was at least twelve degrees higher, the surface temperature in 

 both cases being about 52 degrees. From these observations, it became evident 

 that there are deep currents bringing cold water from the Polar regions to 

 replace the warmer water, which is constantly flowing from the Equator, as well 

 as to make up the loss caused by evaporation in the Tropics ; and that instead 

 of the deep sea being still and stagnant, it undergoes as constan-fc, though, 

 perhaps, more regular changes than the atmosphere. 



The results, as regards the distribution of animal life, were still more 

 interesting and unexpected. The sediment brought up from great depths in the 

 North Atlantic was almost entirely composed of calcareous skeletons of living 

 organisms. Many specimens wore comjiosed chiefly of Foraminifera, sometimes 

 as much as 85 per cent, consisting of one form alone, namely Glohigerina. 

 Certain bodies, which have been named coccoliths and coccosphores, which are 

 evidently products of organisation, have also been found, the former in abun- 

 dance. The great interest of these discoveries arises from the fact that some 

 specimens of chalk consist of little else than Globi(/erin(e, identical with the 

 living form, and that coccoliths and coccospheres are also found in the chalk 

 in no respect different from the recent forms, except in theii- being fossilised. 



The deep-sea mud was found to contain great quantities of a transparent 

 gelatinous substance, exhibiting under the microscope a colourless and structure- 

 less matrix in which granules and coccoliths are imbedded. Professor Huxley 

 regards this as a distinct creature, and has named it Bathiihius, and he thinks 

 that the coccoliths are not independtnt organisms, but that they stand in the 

 same relation to the protoplasm of Bathi/bius as the spicula of sponges or of 

 Badiolaria do to the soft part of those animali. 



