The Days of a Man Cissg 



In the summer of 1889 I carried westward our 

 studies of river fauna. Accompanied again by 

 Mrs. Jordan and assisted by Evermann, Fesler, and 

 Bradley M. Davis — the last two being Indiana 

 University students who later followed me to Stan- 

 ford — I set out to explore the rivers of Colorado, 

 In New Mexico, and Utah. The number of species in 



Colorado ^-hesg sttcams is very much less than in the Alle- 

 ghenies, because of their isolation from the centers 

 of distribution and their greater elevation, two 

 factors which exclude the great body of American 

 types so numerous in the limestone belts of the 

 Mississippi Valley. 



In the course of the work we went into almost 

 every county of Colorado and along innumerable 

 trout streams, the haunts of the state's four species 

 of native trout, all descended from the Cutthroat ^ 

 — Salmo clarki — of the Northwest. These are 

 (i) the Greenback — Salmo stomias — • of the Ar- 

 kansas and Platte (2) the Rio Grande Trout — 

 Salmo virginalis — (3) the Colorado River form — 

 Salmo pleuriticus — and (4) the superb Twin Lake 

 Yellow Fin — Salmo macdonaldi. 

 A splendid The discovcry of the last species was the most 

 nnd interesting scientific episode of the summer. Visiting 



Twin Lakes, a glacial excavation in the midst of 

 the Saguache range and separated into two parts 

 by an old moraine, we found the common Green- 

 back to be very abundant there. As we were pre- 



^ "Cutthroat" refers to the deep red blotch under the throat which dis- 

 tinguishes this species (and its several derivatives) from all other forms. The 

 cutthroat mark is the sign manual of the tribe of Sioux. 



C 334 3 



