306 THE BOTANISTS OF PHILADELPHIA. 



service. Early in 1SG4 he returned to Harvard University 

 to complete his course of study, and in July of that year 

 passed his examination successfully and received his degree 

 of Bachelor of Science. Professor Asa Gray had been his 

 chief preceptor. The winter of 1864-1865 was spent in 

 medical study in the University of Pennsylvania. In 

 March, 1865, he started via Nicaragua to California. He 

 made a narrow escape with his life in Nicaragua, from an 

 attack of Panama fever. In June he was on the Frazer 

 River, on his way to its extreme headwaters, Avhere at 

 Lake Tatleh, in British Columbia, the headquarters of 

 the telegraph company (in that region) were established. 

 During the winter of 1865-1866 he traveled over 2000 

 miles on snow-shoes, and penetrated into regions that were 

 practically unknown. 



He returned the following spring to Philadelphia, and 

 in 1867 received his medical degree from the University of 

 Pennsylvania. The next two years he held the chair of 

 botany in the State Agricultural College. May 27, 1868, 

 he married Martha, daughter of Addison and Elizabeth 

 May, of West Chester. In the spring of 1869 he located as 

 a physician in Wilkes-Barre, and soon acquired a lucrative 

 practice, which was largely surgical in character. He was 

 one of the most active in founding the Wilkes-Barre Hos- 

 pital, which has now grown into one of the large institu- 

 tions of the State. 



During the years 1873, 1874 and 1875, Dr. Pothrock 

 was surgeon and botanist to Lieutenant Wheeler's Exploring 

 Expedition west of the 100th meridian. During these 

 years he made large botanical collections in Colorado, 

 Arizona, New Mexico and California. The results of his 



