636 



SCIENCE. 



[N. S. Vol. IV. No. 96. 



skeleton — the ear bones — of whales are so 

 thickly spread over the surface that they 

 are continually brought up in the dredge, 

 while sometimes a single haul will yield a 

 large number of them. Imagine the count- 

 less generations of sharks and whales 

 which must have succeeded each other in 

 order that these insignificant portions of 

 them should be so thickly spread over that 

 vast area which forms the ocean floor. We 

 have no reason to suppose that sharks and 

 whales die more frequently in the deep 

 ocean than in the shallow fringing seas; in 

 fact, many observations point in the oppo- 

 site direction, for wounded and dying 

 whales often enter shallow creeks and in- 

 lets, and not uncommonly become stranded. 

 And yet these remains of sharks and whales, 

 although well known in the stratified rocks 

 which were laid down in comparatively 

 shallow water and near coasts, are only 

 found in certain beds, and then in far less 

 abundance than in the oceanic deposit. We 

 can only explain this difference by suppos- 

 ing that the latter accumulate with such 

 almost infinite slowness as compared with 

 the continental deposits that these remains 

 form an important and conspicuous con- 

 stituent of the one, while they are merely 

 found here and there when looked for em- 

 bedded in the other. The rate of ac- 

 cumulation of all other constituents is so 

 slow as to leave a layer of teeth and ear- 

 bones uncovered, or covered by so thin a 

 deposit that the dredge can collect them 

 freely. Dr. John Murray calculates that 

 only a few inches of this deposit have ac- 

 cumulated since the Tertiary period. These 

 most interesting facts prove furthermore 

 that the great ocean basins and continental 

 areas have occupied the same relative posi- 

 tions since the formation of the first strati- 

 fied rocks ; for no oceanic deposits are 

 found anywhere in the latter. We know 

 the sources of the oceanic deposit, and it 

 might be possible to form an estimate, 



within wide limits, of its rate of accumula- 

 tion. If it were possible to ascertain its 

 thickness by means of a boring, some 

 conclusions as to the time which ha& 

 elapsed during the lifetime of certain spe- 

 cies — perhaps even the lifetime of the 

 oceans themselves — might be arrived at. 

 Lower down the remains of earlier spe- 

 cies would probably be found. The 

 depth of this deposit and its character at 

 deeper levels are questions of overwhelming 

 interest ; and perhaps even more so is the 

 question as to what lies beneath. Long be- 

 fore the ' Challenger ' had proved the per- 

 sistence of oceanic and continental areas, 

 Darwin, with extraordinary foresight, and 

 opposed by all other naturalists and geolo- 

 gists, including his revered teacher, Lyell, 

 had come to the same conclusion. His 

 reasoning on the subject is so convincing 

 that it is remarkable that he made so few 

 converts, and this is all the more surpris- 

 ing since the arguments were published in 

 the ' Origin of Species,' which in other re- 

 spects produced so profound an effect. In 

 speculating as to the rocks in which the re- 

 mains of the ancestors of the earliest known 

 fossils may still exist, he suggested that, 

 although the existing relationship between 

 the positions of our present oceans and 

 continental areas is of immense antiquity, 

 there is no reason for the belief that it has 

 persisted for an indefinite period, but that 

 at some time long antecedent to the earliest 

 known fossiliferous rocks " continents may 

 have existed where oceans are now spread 

 out ; and clear and open oceans may have 

 existed where our continents now stand." 

 Not the least interesting result would be 

 the test of this hypothesis, which would 

 probably be forthcoming as the result of 

 boring into the floor of a deep ocean ; for 

 although, as Darwin pointed out, it is likely 

 enough that such rocks would be highly 

 metamorphosed, yet it might still be pos- 

 sible to ascertain whether they had at any 



