130 BENTHAM ON PAPILIONACE^ AND CiESALPINIE^. 



siderable degree of uncertainty in the curvature of the nucleus, 

 farther instances of which it would be superfluous to particu- 

 larize at present. I would only add that the ripe seeds of 

 the common Ormosia from Rio Janeiro, (0. nitida, Vogel,) ex- 

 hibit a curious anomaly which has not yet occurred to me in 

 any other genus of the Order. The cotyledons are laterally 

 compressed, their faces being at right angles to the valves or 

 the pod instead of parallel to them, as in other LegiminoscE, 

 the radicle is exceedingly short and straight, and the hilum, 

 slightly indented, produces a corresponding slight indenture 

 in the back of one of the cotyledons. 



Supposing that 1 have not materially en-ed in the forego- 

 ing statements, it will be necessary, in making use of the data 

 they furnish for testing the characters upon which the first 

 subdivisions of Leguminosce may be established, to bear in 

 mmd, that the same principles which regulate the formation 

 of the natural orders themselves should be followed up in their 

 subdivisions into tribes and genera; and especially that purely 

 artificial distinctions derived from a single character should 

 be avoided when they break up natural affinities. Lpon 

 this principle it is that De Candolle placed Adesmia amongst 

 Hedt/saretP, notwithstanding the free stamina, and that Brown 

 left Parkia among Mimosece, though the aestivation ot tiie 

 corolla be imbricated. 



An exception however is generally made, and often vvitn 

 reason, in favour of the form of the embryo, on account oi 

 its supposed physiological importance ; but that importance, 

 in this instance, appears to me to have been much overrated. 

 The ovule in all LegwninoscB is essentially anatropous, that is 

 to say, the chalaza is separated from the hilum by a raphe oi 

 greater or less length, but always very evident, and the foramen 

 is brought down to near the hilum ; there is moreover in almos 

 all the species I have examined, at some stage of its growth, 

 some tendency to a curvature of the nucleus, the distance 

 from the chalaza to the foramen being shorter on the side next 

 the hilum than on the other side; the difference between 

 what is usually called the anatropous ovule and the hemitro- 



