586 Life-histories of Northern Animals 



and watch that turbid river bearing its 400,000,000,000 of tons 

 of mud per annum to the sea,^^ for the manufacture of new 

 continents, we should reaUze that a great many thousand 

 milUon tons of that flood-born sih is simply the debris from the 

 workshop of the Geomyida. 



» Humphrey & Abbott, Delta Survey. 



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