are scattered through his later writings. On April 16, 

 1860, Gen. W. S. Scott issued special order No. 47, di- 

 recting Dr. J. G. Cooper as Contract Surgeon, to report 

 at New York, and to proceed thence to Fort Columbus, 

 Department of Oregon, accompanying a detachment of 

 recruits. This duty terminated Oct. 19, 1860, but his 

 contract was continued to Dec. i of that year. Again as 

 a student we find him collecting along the coast from San 

 Francisco to San Diego. From now henceforward we 

 view the energetic, thoughtful scientific mind. From 

 1 86 1 to 1874 was one continuous series of field observa- 

 tions and studies, the results of which are embraced in 

 his numerous publications until the year 1890. This 

 period will again be examined when we speak of his pub- 

 lications. 



The gigantic struggle of the Civil War found him a 

 student and an active worker in the field of science. 

 Watching this struggle, listening to the roll-calls of the 

 dead, sick and wounded, he again sought service in the 

 army, and on May 24, 1864, Gov. F. F. Law com- 

 missioned him as Assistant Surgeon, 2d Cavalry, Cali- 

 fornia Volunteers, and he served with this regiment until 

 its muster out. Even during this period he did not re- 

 linquish his scientific work, which was that of identifica- 

 tion of individual specimens, of reference, and in publish- 

 ing his observations. He was now a systematist and not 

 a collector. January 9, 1866, he was married to Miss 

 Rosa M. Wells at Oakland, California. 



