292 LEADING AMERICAN MEN OF SCIENCE 



A just appreciation of the value and importance of vertebrate 

 fossils had been acquired by Marsh during his studies and obser- 

 vations abroad, and the supposed poverty of this country in such 

 resources being generally admitted, his genius for collecting was 

 called out anew to meet the deficiency. The years succeeding 

 his return from Europe had been devoted to the careful study of 

 the Cretaceous and Tertiary faunas of New Jersey, from which 

 he had obtained some fossils of interest. He had also made scien- 

 tific excursions into Canada and had investigated the geology of 

 the Connecticut Valley and of New York. But it became apparent 

 to him while on his first short trip to the Rocky Mountains in 

 1868, that paleontological fields far wider than any in the East 

 existed in the West, and he had the genius to comprehend their 

 great possibilities and to realize what personal exploration of the 

 West might yield. The initial journey over the then newly opened 

 Union Pacific Railroad produced results of no small scientific 

 interest, though not strictly pertaining to vertebrate paleontology. 

 From an alkaline lake in Wyoming, he obtained living specimens 

 of larval Siredons, or "fish with legs," as they were called, the 

 remarkable development of which, observed by him after his 

 return to the East, called forth the notable paper: On the Meta- 

 morphosis of Siredon into Amblystoma. 



On this trip he secured various interesting Tertiary fossils 

 that had been thrown out during the excavation of a well in an 

 ancient lake bed at Antelope Station, Nebraska. Among these 

 specimens were the first of the equine mammals that were destined 

 to play so important a role in the list of Marsh's brilliant discoveries. 

 The paper describing his new and diminutive fossil horse (Equus 

 parvulus) appeared in November, 1868. 



This preliminary investigation, confirming the work of Leidy 

 on the vertebrate material collected by the Hayden Survey, con- 

 vinced Marsh of the wonderful fertility of the western country in 

 geological and paleontological resources, and he immediately 

 began preparations for its systematic exploration. Owing to an 

 Indian war in 1869, in the region he wished to explore, his plans 

 were not fully matured until the following year. 



