CONDITION OF THE FLOOR OF THE OCEAN. 319 



Some fishes are blind, while others have veiy large eyes. Phosphores- 

 cent light plays a most important role in the deep sea, and is correlated 

 with the prevailing red and brown colors of deep-sea organisms. 

 Phosphorescent organs appear sometimes to act as a bull's-eye lantern 

 to enable particles of food to be picked up, and at other times as a lure 

 or a warning. All these peculiar adaptations indicate that the struggle 

 for life may not be much less severe in the deep sea than in the shallower 

 waters of the ocean. 



Many deep-sea animals present archaic characters; still the deep 

 sea can not be said to contain more remnants of faunas which flourished 

 in remote geological periods than the shallow and fresh waters of the 

 continents. Indeed, king-crabs, Lingulas, Trigonias, Port Jackson 

 sharks, Cef'atodws, I^epidosiren, and ProtojJterus probably represent 

 older faunas than anything to be found in the deep sea. 



Sir Wy ville Thompson was of the opinion that, from the Silurian 

 period to the present day, there had been as now a continuous deep 

 ocean with a bottom temperature oscillating about the freezing point of 

 fresh water, and that there had alwaj's been an abj'ssal fauna. I incline 

 to the view that in Paleozoic times the ocean basins were not so deep 

 as the}" are now; that the ocean then had throughout a nearly uniform 

 high temperature, and that life was either absent or represented only 

 by bacteria and other low forms in great depths, as is now the case in 

 the Black Sea, where life is practical 1}^ absent beyond 100 fathoms, and 

 where the deeper waters are saturated with sulphureted hydrogen. 

 This is not, however, the place to enter on speculations concerning the 

 origin of the deep-sea fauna, nor to dwell on what has been called 

 "" bipolarity " in the distribution of marine organisms. 



n. 



EVOLUTION OF THE CONTINENTAL AND OCEANIC AREAS. 



I have now pointed out what appear to me to he some of the more 

 general results arrived at in recent years regarding the present condi- 

 iton of the floor of the ocean. I may now be permitted to indicate 

 the possible bearing of these results on opinions as to the origin of 

 some fundamental geographical phenomena; for instance, on the evo- 

 lution of the protruding continents and sunken ocean basins. In deal- 

 ing with such a problem much that is hypothetical must necessarily l)e 

 introduced, but these speculations are based on ascertained scientific 

 facts. 



The well-known American geologist, Dutton, says: 



"It has been much the habit of geologists to attempt to explain the 

 progressive elevation of plateaus and mountain platforms, and also the 

 folding of strata, bv one and the same process. I hold the two proc- 

 esses to be distinct", and having no necessary relation to each other. 



