P R E F A C E. XXlll 



guish two very difficult species. I have also been 

 obliged to correct a few mistakes of my learned 

 friend Dr. Scbrader, 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 Umbellatce considerable 

 indulgence may be requisite, as my performance is 

 almost entirely novel. No reason has been given 

 for taking the injiorescence and bracteas into consi- 

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

 cept the supposed necessity of such a measure. Se- 

 veral botanists have blamed Linnseus 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 recej)tacle, 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 

 w^hich Linnseus was on the whole so successful, 

 though he deserted them in the arrangement of the 



