THE BOTANISTS OF PHILADELPHIA. 11 



published in 1859, was an epoch-making book. It intro- 

 duced the modern period of scientific thought. 



With the exception of Thomas Meehan, Joseph T. Roth- 

 rock, Thomas C. Porter, Charles Pickering, John H. Red- 

 field, Thomas P. James, Benjamin M. Everhart, Rev. Francis 

 Wolle, Mary Treat, William P. Wilson, J. Gibbons Hunt, 

 Emily L. Gregory, John M. Macfarlane, Job B. Ellis, George 

 Rex, H. C. Wood, Henry Trimble, Edson S. Bastin, Ida 

 Keller, Henry Kraemer, J. W. Harshberger and H. C. Porter, 

 very few of the Philadelphia botanists have advanced mate- 

 ria,lly the science of botany according to the progress made 

 in morphology, physiology and taxonomy. The others 

 have unfortunately given their attention to herborizing, 

 and have overlooked the deeper and more interesting prob- 

 lems which are still to be worked out, such as the reasons 

 underlying the geographical distribution of the plants in 

 the region, phenological inquiries or the philosophy of 

 the time of flowering ; physiological problems suggested 

 by growth and development, and ecological questions sug- 

 gested by the environmental conditions. It is to be hoped, 

 however, that with the modern training to be had at 

 several institutions of learning, our botanists will give up 

 discussing the differences between species already described 

 and will devote their energies to advancing modern 

 botanical thought. The facilities for those who desire to 

 obtain a modern botanical training are many. The oldest 

 botanical centre, namely, the University of Pennsylvania, 

 presents, in its Biological School, a place where such 

 instruction may be had. 



A history of the development of botany in connection 



