128 MUD. 



extent, filling up prehistoric Baltics and Mediterraneans, 

 that a glance at the probable course of future evolution 

 in this respect may help us to understand and to realize 

 more fully the gigantic scale of some past accumulations. 



As a preliminary canter I shall trot out first the 

 valley of the Po, the existing mud flat best known by 

 personal experience to the feet and eyes of the tweed- 

 clad English tourist. Everybody who has looked down 

 upon the wide Lombard plain from the pinnacled roof 

 of Milan Cathedral, or who has passed by rail through 

 that monotonous level of poplars and vines between 

 Verona and Venice, knows well what a mud flat due to 

 inundation and gradual silting up of a valley looks like. 

 What I want to do now is to inquire into its origin, and 

 to follow up in fancy the same process, still in action, 

 till it has filled the Adriatic from end to end with one 

 great cultivable lowland. 



Once upon a time (I like to be at least as precise as a 

 fairy tale in the matter of dates) there was no Lombardy. 

 And that time was not, geologically speaking, so very 

 remote ; for the whole valley of the Po, from Turin to 

 the sea, consists entirely of alluvial deposits or, in 

 other words, of Alpine mud which has all accumulated 

 where it now lies at a fairly recent period. We know 

 it is recent, because no part of Italy has ever been 

 submerged since it began to gather there. To put it 

 more definitely, the entire mass has almost certainly 

 been laid down since the first appearance of man on our 

 earth : the earliest human beings who reached the Alps 

 or the Apennines black savages clad in skins of extinct 

 wild beasts must have looked down from their slopes, 



