vi OBITUARY NOTICES. 



regular attendants at the weekly meetings. He jointed the Micro- 

 scopical and Biological Section of the Academy, where he was dis- 

 tinctly in his element. The association with men who were devtoed 

 to this, his favorite study, he enjoyed to the utmost; while they 

 found in him a man remarkably well informed upon the whole field 

 of microscopical research. At the beginning of 1892 he was chosen 

 director of the section, a post which he held for two years. He later 

 became a member of the committee on the award of the Hayden 

 Medal serving until his death, while in 1897 and again from 1900 to 

 1905 he delivered the lectures on geology and mineralogy in the 

 Ludwick Free Courses at the Academy. 



During the time of his first activity at the Academy of Natural 

 Sciences, he became closely associated with Edward D. Cope, who 

 was then professor of mineralogy and geology — later of zoology 

 and comparative anatomy — at the University of Pennsylvania, and 

 who thoroughly appreciated Brown's ability and broad knowledge. 

 In the summer of 1893, having arranged for an exploration of some 

 of the fossil beds of the west in the interests of the Academy, Cope 

 invited Brown to become his associate on the trip, an invitation 

 which he eagerly accepted. Their explorations began at Bismarck, 

 N. D., on July 10, and covered parts of both North and South 

 Dakota, the Cimmaron River District of Oklahoma, the northeastern 

 border of the Staked Plains of Texas and portions of Kansas, com- 

 ing to a close on September 4, at Galena, Mo. Cope paid especial 

 attention to the fossil vertebrates, while Brown devoted himself to 

 the invertebrates. The results of the reconnaissance are set forth 

 in a paper by Cope in the Proceedings of the Academy,^ in wdiich 

 will be found several notes credited to Brown. 



Up to this time Brown had enjoyed excellent health. He pos- 

 sessed an iron constitution and had therefore never found it neces- 

 sary to exercise any care whatever in the matter of exposvire or 

 overwork. Now, however, possibly from overtaxing his strength 

 on the western trip, he sufTered a severe attack of illness, followed 

 in 1895 by another similar attack. This made him very cautious 

 about exposing himself and he seldom went out at night, giving up 



1 " Observations on the Geology of Adjacent Parts of Oklahoma and 

 N. W. Texas," Proc. Acad. Nat. Set. Phila., 1894, pp. 63-68. 



