POPULAR EXPLANATION. 17 



of the State Hospital for the Insane, at Mt. Pleasant, who 

 presented a series of carefully preserved specimens of the 



j. — ~ ~~ ., ^^"VMu ■ojj.ujLi^jLj dgiceu in ine 



opinion that after all the stratified rocks had been formed, 



there was a time when the whole northern hemisphere as far 

 3 



