64 PIONEERS OF SCIENCE IN AMERICA. 



Flora of Pennsylvania as in preparation, Muhlenberg con- 

 cluded that as that author had seen his manuscripts and her- 

 barium, it would not be necessary for him to publish anything 

 except a few additional notes which he might make during the 

 year, and a Floral Calendar. " Excuse my enthusiasm for 

 science," he wrote to Dr. Cutler, in 1792, "which has given me 

 so many pleasant hours, and which, I know, has been cultivated 

 by you with great success. Botany needs your co-operation, 

 and when you have prepared a full table, please leave a few 

 fragments for me." It was this readiness to give credit to 

 the merit of others, combined with his clear vision of the con- 

 fusion that threatened to arise from the continuance of plan- 

 less labours, that decided him as early as 1785 to bring out a 

 plan for common labour in making up the Flora of North 

 America. He came to the Philosophical Society again in 1790 

 or 1791 with this plan. "1 repeat," he writes, "my formerly 

 expressed desire that a number of my learned countrymen 

 should unite in botanical investigation and send in their floras 

 to the society for revision and publication, so that by combi- 

 nation of the floras of the different States we may obtain a 

 flora of the United States which shall rest on good and definite 

 observation." While this plan was not carried into execution 

 through the medium of the American Philosophical Society, 

 Muhlenberg again and again returned to it in his extensive 

 correspondence. Thus he wrote : " Others should do the same 

 (that is, search out the flora of the neighbourhood of their 

 homes), and, after collecting material for a dozen years, let a 

 Flora of North America be written." Further, " I first sent in 

 a sketch, and in 1790 an index of all the plants that grow here, 

 in the expectation that my botanical friends would join in 

 working up the floras of their several States, so that in about 

 ten years a more general work might be undertaken." And in 

 another place : " If the botanists continue to proceed in the 

 way they are going, in a few years all will be confusion. In 

 order to be sure, we should confer with one another. For this 

 purpose I have printed my Index before publishing full de- 

 scriptions." A letter to Dr. Cutler, of November 12, 1792, 

 goes more into particulars ; it reads : " You have made the 

 beginning of a Flora of New England, and all friends of 

 botany wish that you would go on and complete the work. 

 Let each of our American botanists do something, and the 



