MICRO-ORGANISMS 



One needs, however, first to take some 

 exercises in thought expansion before this 

 story can be fully appreciated. Limestone 

 strata, as we have said, make up a great 

 part of the crust of the globe. But when 

 we study how the strata succeeded one 

 another in time, we become staggered with 

 the signs of the presence of the Eocene 

 Canadense in the limestone underlying 

 the Laurentian rocks. Whole mountain 

 ranges then towered above the sea and 

 sank again; sea became land and land sea; 

 climates changed from warm to cold and 

 back again; environment changed and 

 changed, and yet these foraminifera are 

 still at their ancient doings the same as 

 ever, so that if the present ocean bed were 

 raised as in former times, new chalk cliffs 

 would appear as of old. As Dr. Carpen- 

 ter says, these foraminifera as long ante- 

 dated the first fossils of multicellular 

 form in the Lower Cambrian as these 

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