THE BOTANISTS OF PHILADELPHIA. 239 



To Walling & Gray's "Topographical Atlas of Pennsylvania" 

 (Philadelphia, 1872), he furnished a "Sketch of the Flora 

 of Pennsylvania," with a colored map, and to Gray's " Atlas 

 of the United States," 1873, a " Sketch of the Botany of the 

 United States," also with a colored map. In addition to 

 these he has contributed from time to time many valuable 

 articles to the botanical journals, and is in constant corres- 

 pondence with leading naturalists at home and abroad. He 

 is an honorary member of the American Philosophical 

 Society and the Academy of Natural Sciences, Philadelphia ; 

 of the Davenport Academy, Iowa ; an active member of 

 the Torrey Botanical Club, New York, and a Fellow of the 

 American Association for the Advancement of Science. 



Founders' Day at Lafayette College (October 20, 1897) 

 was observed by paying tribute to the services rendered by 

 Professor Porter to the cause of science, of religion and of 

 literature. Professor William B. Scott, of Princeton, spoke 

 on Dr. Porter's contribution to geological science ; Dr. John 

 M. Crawford, of Cincinnatti, spoke of Dr. Porter as a 

 pioneer in Finnish Literature. Dr. N. L. Britton, Director 

 of the New York Botanical Gardens, referred to Dr. Porter 

 in his address on " The Progress of Systematic Botan}^ in 

 North America," in these words : " During the last half of 

 the century Professor Porter has contributed information 

 and material of great value to practically all the mono- 

 graphers of groups or of floras during that period ; his col- 

 lecting and critical observations began shortly after his 

 graduation from Lafayette College in 1840, and have con- 

 tinued uninterruptedly for nearly fifty years. Always 

 ready and anxious to aid, he has supplied to other authors 

 for more information than he has personally published, so 



