18 LETTER I. 



Larkspur belongs to Ranunculaccse, you will have no 

 diific'ulty in perceiving that the true Aconite (Aconi- 

 tum), is also of the same natural order ; for the re- 

 semblance of these two is too striking to be mistaken. 

 The true Aconite, which yields to no plant in the vi- 

 rulent poison of its roots, has all the structure of the 

 Larkspur, except that the upper leaf of its calyx has 

 not any horn, but is very large, and resembles a 

 sort of helmet, overshadowing all the other parts of 

 the flower. In consequence of there being no horn 

 to the upper leaf of the calyx, the two uppermost 

 petals, which have horns, are forced to hide them be- 

 neath the helmet, instead of inserting them into it. 

 With these differences the Larkspur and the true 

 Aconite are formed nearly alike. 



PcBonies are the last plants I need mention, as be- 

 longing to the Crowfoot tribe. They have a calyx 

 which resembles green leaves, and which never drops 

 off" ; in other Ranunculaceae, the calyx often drops off, 

 even before the petals ; in this respect, Pseonies are 

 unlike the rest of the Crowfoot tribe ; but they have 

 the two essential marks of distinction in the carpels 

 iind the stamens. 



Let me recommend you to procure, if possible, all 

 the plants that have thus been enumerated, and 

 to compare them with one another till you fully under- 

 stand their resemblance, which you may very readily 

 do ; and then you will find, that to know the struc- 

 ture of the common Crowfoot, is, indeed, as I said in 

 the beginning, to know the properties and general 

 character of a large natural order. 



