274 THE JUSSIEUS AXD TPIE NATURAL METHOD. 



more apparent and easy to be observed. It bas been tbougbt tbat tbis double 

 object migbt be fultillecl by joining to tbe essential cbaracters, wbicb are sometimes 

 little apparent, certain accessory cbaracters, wbicb are constant and always visi- 

 ble, and wbicb indicate tbe existence of the former by associating tbe corolla 

 witb tbe stamens, in order to designate tbe classes." (Memoii- of 1774.) 



Laurent has since said, (1824:) "It would be necessary to adhere to tbis 

 number" (tbe number seven of Bernard,) ''if, in order to avoid all exception or 

 variation, the classes could only be founded on invariable cbaracters. I3ut if it 

 be observed that tbe number of families now adopted amounts to nearly one 

 Ijundred and fifty, and is consequently qniie considerable for eacb class, the 

 necessi'y will be felt of forming new subdivisions, without deviating, however, 

 ii'om admitted principles, and by always adhering to cbaracters of the greatest 

 lvalue. That which first presents itself, after the invariable, is the character 

 derived from the mediate or immediate insertions, or, otherwise, from the corolla 

 considered as existent or null, as monopetalous or polypetalous. Although it be 

 subject to some variations, it is still that wbicb presents the fewest, and by 

 employing it for the subdivisions, tbe number of classes can be multiplied, which 

 diminishes embarrassment in the arrangement of families, and may much facili- 

 tate study. It is true that tbis character is of no utility in dividing either the 

 acotyledons, the flowers of wbicb are too little apparent, or tbe tbree classes of 

 monocotyledons, in wbicb tbe corolla does not exist, since tbe part which was 

 long taken for such is a true calyx. It is in tbe dicotyledons alone, then, tbat 

 we can employ the character of the insertions, whether mediate, simply immediate, 

 or essentially immediate ; or, in other terms more easily I'cmembered, the cbaracter 

 of monopetalous, polypetalous, apetalous plants. We thus establish, thougb 

 admitting of some exceptions, in each of tbe tbree classes of dicotyledons, tbree 

 subdivisions, without deviating from the principles adopted, and the number of 

 dicotyledinous classes would then be raised to nine. Further, tbe subdivision 

 or class of monopetals with epigynic corolla, or corolla borne on the pistil, may be 

 separated into two, according to the character of their stamens, distinct in one 

 of its divisions, united in a sheath by tbe anthers in the other, which compi-ises 

 solely tbe great series of composite plants. Tbis separation, wbicb, in the 

 dicotyledons, adds a tenth cbiss, does not separate families and conflicts with no 

 affinity." 



He afterwards adds : "It bas already been stated that, in order to arrange tbe 

 families more easily, it Avas necessary to multiply tbe great divisions, always 

 adhering, however, to the most solid characters, and we have seen how it has 

 been practicable to augment tbis number of classes in tbe dicotyledons through 

 considerations derived from the corolla. It bas appeared to us, nevertheless, tbat, 

 with a view to facility of st-udy, an object which should not be neglected, it 

 was necessary, in order to have in the great divisions principal characters easy 

 of apprehension, and to approximate a little in this point to the method of Tourne- 

 fort, founded on tbe corolla, to give the preference to mediate and immediate 

 insertions over hypogynic, perigynic and epigynic insertions, and not to follow 

 rigorously tbe first principles established. We shall have tbe same classes, but 

 presented, in the dicotyledons, according to another series. Thus, by leaving 

 tbe four classes of the first two grand divisions to subsist in their integrity, and 

 without any change, we shall, in the first place, distinguish the dicotyledons into 

 apetalous, monopetalous and polypetalous plants. In the apetalous, or those with 

 essentially immediate insertion, we shall distinguish three classes witb epigynic, 

 perigynic, and hypogynic stamens. If we next pass to plants Avitha monopetalous 

 corolla or mediate insertion, and if we remember tbat the insertion of this corolla 

 then becomes tbe essential and primary character, we shall subdivide the mono- 

 petals into the hypogynic, perigynic and epigynic corollas, and the epigymu will 

 be further divided into synanthene, having united anthers, and chorisautherre, 

 having distinct anthers. The polypetalous plants, or those having the inserlioa 



