hunter's posthumous paper on fossils. 333 



of which was felt simultaneously through a space of 1200 miles, from 

 north to south. St. Jago, Valparaiso, and other towns were much 

 injured by that great commotion. 



The shores of the Bay of Conception were similarly affected during 

 the great earthquake of February 20th, 1835. Mr. Darwin, who felt 

 the shock, estimates the upheaval of the land round the bay at two or 

 three feet. At the island of S. Maria, about 30 miles distant, " Captain 

 FitzEoy found beds of putrid mussel-shells, still adhering to the rocks 

 ten feet above high-water mark : the inhabitants had formerly dived at 

 low- water spring-tides for these shells." But the elevating force which 

 operates more gradually, and without such violence, is not less important, 

 and its effects are appreciable within the comparatively restricted period 

 of human history. Thus it has been determined by successive experi- 

 mental observations that the shores of the Baltic are rising at the 

 estimated rate of four feet in a century. Ancient beaches extending 

 along certain parts of the British coast, at elevations varying from ten 

 to one hundred feet above the present sea-level, attest the upraising of 

 such ' extents of the surface of the earth.' 



Hunter by no means exaggerates the effects of the igneous or elevating- 

 force. He perhaps failed to comprehend its full influence in repeated 

 operations during a vast period of time. He hesitated, e. g., in apply- 

 ing it to the upheaval of such ridges of mountains as had been traced 

 extending with a certain regularity for many hundred miles. " At 

 least," he says, " the eruptions that now take place on the land do 

 not produce such." It is easy to conceive, however, what would be 

 the result of a succession of such lifts as have been observed to operate 

 upon the base of the Andes in our own times, if continued through the 

 ' many thousand centuries ' that Hunter so often appeals to. Geology, 

 indeed, now finds no numerical term adequate to embody the idea of 

 time, which the contemplation of its phenomena forces on the mind. 



With regard to the agency of animal life in forming or altering the 

 earth's crust, Hunter, by virtue of his comparative anatomy and phy- 

 siology, was, perhaps, the best able of any philosopher in his day to 

 appreciate this now generally recognized geological force. 



Although unaided by such microscopes as have revealed to Ehrenberg 

 and others the animalcular origin of immense tracts of calcareous and 

 siliceous earth, Hunter, after showing that the earthy materials of the 

 skeletons of many animals, and especially of shell-fishes, star-fishes, and 

 zoophytes, were the same earth as composed part of the globe, and as 

 imperishable as such earth, boldly affirms that " a large portion of the 

 globe is indebted to animals for such calcareous earth," and concludes 

 by saying, " and indeed many of our islands are no more than supe"r- 



