6 To the River Plate and Baek 



order to which the huger beasts of which I have spoken 

 have been assigned by systematists. 



One of the great formations of rock belonging to the 

 Mesozoic age is known by geologists as the Jurassic, 

 so called because it is finely developed in the Jura 

 Mountains. But this formation is not confined to 

 Europe. Jurassic rocks occur in all parts of the globe. 

 They have become the hunting-ground of those who 

 desire to obtain well-preserved specimens of dinosaurs. 

 There are great exposures of the Jurassic among the 

 Rocky Mountains in Wyoming, Colorado, Utah, and 

 other States. 



One of the most indefatigable students of the extinct 

 life of the North American continent was the late 

 Professor Othniel C. Marsh of Yale University. He 

 consecrated his life and the fortune bequeathed to him 

 by his uncle, the celebrated philanthropist, George 

 Peabody, to the task of elucidating the story buried in 

 the strata. He died a poor man, before the work he 

 had undertaken had been completed. Generations 

 of men are likely to follow him to the grave before the 

 whole story is rescued. Among the strange forms, 

 fragments of which were obtained for Professor Marsh 

 by his assistants working in the Jurassic strata of 

 Wyoming, was that of a dinosaur, to which he gave the 

 name of Diplodocus. The word is compounded from 

 the Greek words CITAOCX; (diploos), meaning ''double," 

 and co/.6<; (dokos), meaning "beam," or " rafter." 

 In the Sermon on the Mount the word dokos occurs in 

 the well-known passage where The Great Teacher says, 

 ' First cast out the beam [rafter] out of thine own eye ; 

 and then shalt thou see clearly to cast out the mote out 

 of thy brother's eye." The reason Professor Marsh 

 chose these words in coining a name for the newly 



