The earliest robsp;in the record are called by geologists the Azoibsp;rocks, bebsp;they show no trabsp;of life.

Great areas of the Azoibsp;robsp;lie uncovered in North Ameribsp;and they are of subsp;a thiess that geologists sider that they reprent a period of at least half of the 1,600,000,000 whibsp;they assign to the whole geologibsp;record.

Let me repeat this profoundly signifit fact.

Half the great interval of time sinbsp;land and a were first distinguishable on earth has left us no trabsp;of life.

There are ripplings and rain marks still to be found in the rocks, but no marks nor vestiges of any living thing.

Then, as we e up the record, signs of past life appear and increa.

The age of the world’s history in whibsp;we find the past trabsp;is called by geologists the Lower Pal?ozoibsp;age.

The first indications that life was astir are vestiges of paratively simple and lowly things: the shells of small shellfish, the stems and flowerlike heads of zoophytes, aweeds and the trabsp;and remains of a worms and crustacea.

The earliest robsp;in the record are called by geologists the Azoibsp;rocks, bebsp;they show no trabsp;of life.

Great areas of the Azoibsp;robsp;lie uncovered in North Ameribsp;and they are of subsp;a thiess that geologists sider that they reprent a period of at least half of the 1,600,000,000 whibsp;they assign to the whole geologibsp;record.

Let me repeat this profoundly signifit fact.

Half the great interval of time sinbsp;land and a were first distinguishable on earth has left us no trabsp;of life.

There are ripplings and rain marks still to be found in the rocks, but no marks nor vestiges of any living thing.