208 WHAT IS LIFE ? 



broadcast, able to prognosticate the future from the 

 present. What is his role in the great Eternity before 

 him? 



In this brief and therefore imperfect record of the 

 physical history of our world, largely abstracted from 

 Sir Archibald Geikie's "Text-Beck of Geology," the 

 following facts must be always kept steadily in mind. 

 Firstly, the number of distinct layers of deposits is abso- 

 lutely enormous, and it is not possible to numerically 

 value them. These deposits are of every conceivable 

 material, sometimes clay, then gravel, or sand, or sand- 

 stone, or limestone, &c. Sometimes the layers were 

 deposited in salt water seas or oceans, sometimes fresh 

 water rivers or lakes. There is only one definite order 

 of formation, the newer is always laid on the older, and 

 thus we are able to trace the order of deposition. 

 Secondly, the organic remains of life which lived on 

 land must of necessity be of the rarest description. 

 Only some accident would permit the bones of land 

 animals, for they are the principal remains, to be 

 deposited in the bed of the waters, and with a few 

 exceptions this is the process by which these remains 

 have been preserved. On the other hand, of the life 

 which lived in water most abundant remains are found. 

 Thirdly, the most important idea to grasp is, every 

 organism except the most simple was built up of cells 

 and the material secreted by these cells. Just as the 

 material of which the shell of an oyster is composed is 

 secreted by the cells the living composite individual 

 so were these fossils secreted by living cells. Every 

 cell is an intensely complex group of molecules, every 

 molecule is a group of atoms, and the grouping of these 

 atoms has been the result of the superior power of 



