198 To the River Plate and Back 



the pampas the estancieros are in the habit of saying 

 that the land is not good, and it is said in praise of a 

 tract offered for sale that it is sin to sea, free from con- 

 cretionary beds. To some extent this lime is no doubt 

 due in its origin to the solution and redeposition of 

 particles of the fine alluvium derived from the erosion 

 of limestone rocks; to some extent it is also no doubt 

 due to the gradual solution and redeposition of the lime 

 from shells, bones, and other organic remains, which 

 were left upon the surface as generation after generation 

 of living things laid down and died. In Switzerland 

 the small concretions in the loess are known by the 

 peasants as ' Loess-kindl ' -loess-babies because of 

 their curious forms, sometimes suggesting those of 

 human beings. In the Mississippi Valley in places 

 there are considerable deposits of loess, and the concre- 

 tions found in them are often spoken of as ;< fossil 

 potatoes' because of their resemblance to the tubers. 

 The pampas are overlaid by loess, and, except along 

 some of the great rivers of China, there is no such 

 extensive deposit of loess anywhere else in the world. 

 The thickness of the loess in Argentina is very remark- 

 able. It varies of course, but Dr. Roth tells me borings 

 show that in some places it is many hundreds of feet in 

 depth. The time necessary for the slow deposition of 

 such beds by eolian agencies must have been very 

 great. Dr. Roth is of the opinion that all periods of the 

 Tertiary may be represented in these beds from the 

 Eocene up to the latest Pleistocene, and in fact that 

 they have been in process of formation in South America 

 from the dawn of mammalian life to the present time. 

 I am not prepared to either affirm or deny this view. 

 The observations made in a day or two do not suffice 

 to enable anv man to reach conclusions upon such a 



