6 



siological or systematic botany, that has been made in 

 our (lays, though I am by no means certain with whom 

 it originated, relates to the numerical difference in the 

 parts of fructification between the monocotyledones and 

 dicotylcdones. In the formei', these parts are regulated 

 by the number 3 or its compounds; in the latter by 5. 

 I'he exceptions in each case, consisting of partial sup- 

 pressions, or subtractions, relative to some part or other, 

 follow the same rules. Thus one third is suppressed in 

 the styles or stigmas of Grasses and some Calamayncc ; one 

 fifth in the calyx, corolla and stamens of some Bicornes, 

 and other dicotyledones naturally decandrous; witness 

 Erica, Vacciniiim, Epilobiim, &c. In Scitaminecv and Or- 

 cJiidece rudiments of 2 abortive stamens are observable, 

 indicating a suppression of two thirds ; in Cypripedium 

 indeed, which has 2 perfect stamens, only one third is 

 wanting in those parts. The Orchidece are universally al- 

 lowed to be monocotyledonous, or as some sayacotyledon- 

 ous, which makes no real difference. Their parts of fruc- 

 tification are therefore governed by the number 3, not 5. 

 It is contrary to every analogy to suppose they have 

 either 5 calyx-leaves, or 5 petals ; with a solitary organ 

 which, to avoid the use of the Linnsean term nectary, is 

 called a lip, though this organ secretes and contains 

 honey. But to take the 3 outer leaves of the flower for 

 a calyx, and the other '?, (which are alternate therewith, 

 as well as ranged in an interior circle,) for the corolla, 

 composed of 2 petals and a nectary, the last being most 

 correctly a part of the corolla, appears to me perfectly 

 intelligible and consistent. My distinguished friends 

 Professor de Jussieu and Mr. Brown, from whose en- 

 larged views the world has derived so much instruction, 

 will, I am confident, pardon me if a search after truth 

 leads me here to differ from them. The latter has in- 

 deed, in the Hortus Kewensis, so far altered the theory 

 he originally adopted from Jussieu, as to term corolla in 

 these plants, what he had caWed periant/iinm, and the can- 

 dour of such an alteration does him the highest honour. 

 The most eminent botanists have differed no less widely 

 in the foundation of their generic distinctions of Orc/ii- 

 dece. Linnaeus takes his characters chiefly from the form 

 of the nectayy, and especially of its posterior termination^ 

 without adverting to the anther, Haller first noticed the 

 differences in this latter part, of which however he by no 



