168 



CLASS MONADELPHIA. 



Fig. 146. 



notch at the top, and such as are entire. The Pepper-grass 

 {Lejndium) and the shepherd's-purse {Tlilaspi) afford examples 

 of this order. At Fig. 146, d^ is a representation of the silicula 

 or pod of the Thlaspi. The plants found here belong to the 

 natural family Siliquosce^ the properties of which are nutritious 

 and medicinal. 



2-11. The second Order ^ Siliquosce^ con- 

 tains cruciform plants with lo7ig and nar- 

 roio silu2ii€s; as the radish and mus- 

 tard. The cabbage {Brassica) is an ex- 

 otic ; the turnip is a species of the same 

 genus. Fig. 146, a^ rejDresents the wall- 

 flower {C heiranthus) ; the calyx consists 

 of four oblong sepals ; the petals are obo- 

 vate, spreading with claws as long as the 

 calyx. At h appear the six stamens di- 

 vested of the petals ; the ovar}^ is cylin- 

 drical, as long as the stamens ; c shows 

 the silique or pod ; the valves are con- 

 cave, and a thin membraneous partition divides the silique into 

 two parts. In this order there a2:)pears a want of symmetry in 

 the number of stamens compared with the floral envelopes. 

 The two pairs of long stamens may, however, each be considered 

 as one dmided stamen (a dedoublement\ which would reduce 

 the number to four. This view is confirmed by the fact that 

 the two shorter stamens have teeth on each side, while the 

 longer ones are toothed but on one side. The floral type of 

 Cruciferse is regarded as quaternary ; four sejyals^ four petals^ 

 recejDtacle four staminiferous glands^ four stamens.^ snidfour 

 carpels^ two of which are abortive. In some species of fteris 

 (candy-tuft) the floral organs have been seen to exhibit in all 

 their parts this quaternary, or normal arrangement. 



LECTURE XXXII. 



MONADELPHIA, ONE BEOTHEEHOOD. 



242. We are now to examine the hvtherhoods ; Monadelphia 

 meaning one, and Diadelphia two brotherhoods, in allusion to 

 the manner in which the filaments are connected in one or two 

 sets. The orders in these classes depend upon the number of 

 stamens. 



B41. Order Siliquosae — Want of Bymmetry explained. — 242. The brotiierhoods. 



