Scien Ufip ^ lntelU(J<^nce---Ge(^loyy. 95§! 



njay have predominated over other vertebrata throughout wide areas ; 

 but tht-re is no evidence that the adaptation of the fauna, as above 

 explained, had been governed by any law of progressive develop- 

 ment. In those classes of the invertebrata which were best known, 

 and fully represented in a fossil state at all geological periods, the 

 oldest or Silurian fauna was as highly developed as the correspond- 

 ing fauna in the recent seas. Our ignorance of the inhabitants of 

 the ancient lands was the chief cause of our scanty acquaintance 

 with the highly-organised beings of ^Vefriiote epochs. — {Literary 

 Gazette, No. 1824, p. 17.) , ...p,,,-^,,^,. 



3. Dcsor on the JDrift of Nortn America. — The drift is the last 

 piiase of any importance through which the earth passed before it be- 

 came fitted for the habitation of man. Were it not for these deposits, 

 a great portion of this continent, including the district embraced in this 

 report, would have been a waste of naked and barren rocks, covered 

 partially with heaps of dry sand, or rough detrital materials. Through 

 the long-continued agency of water, these materials have not only 

 been reduced and dispersed, but also mingled in such proportions as 

 to afford a most appropriate soil for vegetable and animal life. 

 When afterwards the rise of the continent caused the waters to 

 recede within their present limits, they left behind them those wide 

 drift-covered plains, destined to become, in the lapse of time, the 

 seat of an industrious, intelligent, and prosperous nation. We think 

 ourselves justified in considering the period when the waters, after 

 having done their work, began to recede, as the beginning of that 

 new and grand era which has been properly called the Era of Man, 

 and of which the alluvial period is the introduction. — [American 

 Jp^rnal of Science avid Arts, vol. xiii.. No. 37, 2d Series, 



, C Lieut, Charles Henry Davis on the Connection between Tides 

 and Alluvial Deposits. — So long ago as September 1848, he wrote, 

 " I have recently arrived at some interesting conclusions concerning 

 the connection between the tides and other currents, and the alluvial 

 deposits in the depths and on the borders of the ocean ; and my 

 views bear out the theory that attributes the principal changes in 

 the conditions of the earth's surface to causes now in operation. I 

 am able, I believe, to shew a permanent and mutual relation between 

 the local and general tides on the one hand, and the eastern border 

 of the United States on the other ; between the shores cf the Gulf 

 of Mexico, and the currents by which they are washed. The sandy 

 deposits on the Atlantic border are remarkable in outline as well as 

 in quantity. A narrow strip on the coasts of Florida and Georgia 

 spreads out into those prominent capes and enormous banks and 

 shoals which give such a peculiar character to our navigation. On 

 the shores of Europe the vast deposits of similar material at the 

 bottom of the Bay of Biscay, and in the North Sea, are to be traced to 

 the same laws of tidal action. The theory will also account for simi- 



.^'^liiqe-i Of* 



