758 LOUIS AGASSIZ. 



tracts of the valley to the north of it free 

 of ice, so that large glacial lakes could be 

 formed, and seem, indeed, always to have ex- 

 isted along the retreating edge of the great 

 southern glacier. The natural consequence 

 is that there are everywhere stratified ter- 

 races without border barriers (since these 

 were formed only by the ice that has van- 

 ished), resting at successively higher or lower 

 levels, as you move north or south, upon un- 

 stratified drift of older date ; the northern- 

 most of these terraces being the oldest, while 

 those further south belong to later steps in 

 the waning of the ice-fields. From these 

 data I infer that my suggestion concerning 

 the trend of the strise upon the polished and 

 glaciated surface of the vicinity of Talca- 

 huana, alluded to in the postscript of my last 

 letter, is probably correct. . . . 



At Santiago Agassiz rested a day or two. 

 Here, as everywhere throughout the country, 

 he met with the greatest kindness and cordial- 

 ity. A public reception and dinner were 

 urged upon him by the city, but his health 

 obliged him to decline this and like honors 

 elsewhere. Among the letters awaiting him 

 here, was one which brought him a pleasant 



