2 To the River Plate and Back 



in such museum as might be designated by the proper 

 authorities. 



At this point the reader, unless he is well versed in 

 the recent progress of paleontological research, may 

 well ask: "What is a Diplodocus?'' He will find him- 

 self in the same frame of mind as the French Secretary 

 of Legation who was being entertained in Philadelphia, 

 and came to his host with a troubled countenance 

 saying: 'I have been here for some days and I hear 

 everybody speaking about ze Biddies. Vat ees a 

 Biddle? Je ne comprends pas." 



Before answering the question, a little preliminary 

 discourse of a semi-scientific nature is required for 

 the enlightenment of the uninitiated. Should any one 

 of my brethren of the Geological Society of America 

 chance upon this book, he is at liberty to omit the 

 perusal of what follows on the immediately succeeding 

 pages. 



The world in which we live is a very old world. 

 Many things have happened during its long existence, 

 and one of these, which is of interest to all of us, is the 

 evolution upon its surface of plants and animals. No 

 recording angel has written down the story of this 

 process, and we are left to decipher it, as well as we 

 may, from the records, more or less confused and frag- 

 mentary, which we find in the sedimentary rocks. 

 These are the rocks, which once were mud and beds of 

 sand, in which were buried bits of wood, leaves, shells, 

 and the bones of various animals. In the lapse of 

 ages the mud and the sand became cemented together 

 and hardened, carrying with them as integral parts of 

 their substance the remains which were included in 

 them. These sedimentary rocks in the aggregate are 

 very thick. It has been estimated that they have a 



