166 



WHAT IS LIFE ? 



Although we cannot give moments of date when the 

 alterations took place (neither can we do this generally 

 in very ancient human history), sufficient facts are now 

 made known to us in order to grasp the absolutely stupen- 

 dous time required for the deposits containing organic 

 remains now found to exist in the crust of the earth. 1 



1 " The argument from geological evidence indicates an interval of 

 probably not much less than 100 million years since the earliest forms 

 of life appeared upon the earth, and the oldest stratified rocks began 

 to be laid down." (" Text-Book of Geology," Sir Archibald Geikie, 

 F.B.S., 3rd edition, 1893, p. 58.) 



It is questionable if such deductions, however, are not vain, and 

 why P Because the past is but a repetition of the present. At the 

 present moment the forces of ^Nature are destroying the records of 

 the past. A few hours' direct observation teaches much more than 

 reading volumes of books. Perhaps there is no locality more favour- 

 able for a Londoner to make these observations than the Isle 

 of Wight, and a delightful walk round the coast reveals in a 

 wonderful way the destroying influences now going on. The diagram 

 below shows the structure of the island. It is from Mantell's 

 " Geological Excursions round the Isle of Wight." 



Fig. 19. Diagram illustrative of the geological structure of the Isle of 

 Wight, c, Upper and Lower chalk; /, Upper Greensand ; g, Gault; 

 g, s, Lower Greensand ; w, Wealdeu. 



At the south-east, near Dunnose Point, we find layers of large 



