\ 



United States EnCtINEEh OfficEj 

 Explorations and Surveys west of the 100th Meridian, 



'^Washington J J), (7., June 8, 1S74. 



Sir: I have the honoi' to forward herewith reports upon portions of 

 the botanical collections made iuthe years 1871, 1872, and 1873, by Mr. 

 Sereno Watson, and Dr, J. T. Rothrock, acting assistant surgeon United 

 States Army, and suggest the propriety of their separate publication. 



The manuscript material already gathered for the natural-history 

 volume of the survey reports is so voluminaus that tlie parts referring 

 alone to the collections of animalsj birds, insects, &c-, will occupy more 

 than 400 quarto pages. 



The interest evinced by the numerous requests received for the re- 

 ports upon the various subjects intrusted to the survey for examination 

 leads to this request. 



Very respectfully, your obedient servant, 



GEO. M. Wheeler, 



First Lieutenant Corjys of Engineers^ in charge. 



Brig. Gen. A. A. Hu^iphreys, 



Chief of jEjngineer&. 



