PREFACE. XX111 



guish two very difficult species. I have also been 

 obliged to correct a few mistakes of my learned 

 friend Dr. Schrader, and of other distinguished 

 writers, concerning these plants, and their near 

 allies the Grasses ; all which I submit, with due 

 deference, to the reconsideration of the parties con- 

 cerned. In the order of Umbellate considerable 

 indulgence may be requisite, as my performance is 

 almost entirely novel. No reason has been given 

 for taking the infloresce?ice and bracteas into consi- 

 deration, for denning the genera of this tribe, ex- 

 cept the supposed necessity of such a measure. Se- 

 veral botanists have blamed Linneeus for this dere- 

 liction of his own principles, and have run into a 

 contrary error, by fixing on the seeds alone for ge- 

 neric characters. The able Professor Sprengel has 

 had recourse to the seeds, but he still adverts to 

 the bracteas. Professor Hoffmann has adhered to 

 the old principles, with many minute details. By 

 a full investigation of all the organs of fructifica- 

 tion, and by distinguishing the tumid bases of the 

 styles from the floral receptacle, things hitherto 

 confounded, I have characterized the Umbelliferous 

 plants like the rest, by the parts of the flower and 

 fruit alone. In doing this I have kept the exotic 

 species in view, of which the Linnsean collection, 

 and those of many botanists of Switzerland, with 

 the Greek herbarium of my lamented friend Pro- 

 fessor Sibthorp, have furnished me with almost all 

 that are known. The principles I have adopted 

 prove amply sufficient, being no other than those 

 by which Linnreus was on the whole so successful, 

 though he deserted them in the arrangement of the 



