PREFACE. 



THE idea has been long entertained, of collecting the 

 Natural Productions of Chester County, with special 

 reference to the elucidation of its Prospective History. With 

 this object in view, THE CABINET OF NATURAL SCIENCE OF 

 CHESTER COUNTY was organized, in the year 1826. From 

 that time forward, several of its members engaged, with 

 ardor, in the work. But it was soon discovered that the 

 field for research was too ample the labor too great the 

 laborers too few, for this desideratum to be speedily attained. 

 Yet, much has been accomplished. 



The indefatigable industry, and scientific acumen, of the 

 late Doctor William Darlington, has left little more to be 

 done, in Phxnogamous and Filicoid Botany, within our 

 limits. , His little FLORULA C^ESTRICA appeared in 1826. It 

 was followed, eleven years after, by the more extended, and 

 complete, FLORA C^ESTRICA. This was greatly enlarged, and 

 improved, in a third edition, in 1853. It was also rendered 

 more comprehensive, by the addition of the remaining 

 Anophyta (the Mosses and Liverworts} furnished by Thomas 

 P.James; and the Thallophyta (the Lichens and Collemas} 

 by Dr. E. Michener. 



