PHANEROGAMIA : FLOWERS. 



367 



215 



the individual rudiments of the leaves are formed 

 quite separately, and always before the carpels : 

 it is by a later process that they become blended 

 together into a ring. In the second case, the 

 ring, or discus, originates at once as a perfectly 

 uniform whole, and always after the appearance 

 of the carpels, by a simple extension of the axis 

 already existing, though this may not itself 

 bear foliar organs on this part (as in Reseda). 

 This last case exists in the Boraginece and La- 

 biatce, in the discus (the so-called gynobasis}. 

 Trapa, Convolvulus, and the family of the Scro- 

 phnlarice, offer good examples of the first case. But 

 in these another difficulty presents itself, which 

 it will require the most comprehensive examin- 

 ation to conquer; namely, in these there appears 

 to occur either a division into two groups, of 

 which one has four-membered and the other five- 

 membered circles in the flower, or they are both 

 four-membered, and the perfect floral parts of 

 the one group only appear five-membered be- 

 cause the individual members of the same are unequally developed : 

 thus one leaf of the innermost circle will form the unilateral disc, while 

 the other three become stamens, and with one or two leaves of the next 

 circle form the four or five stamens, &c. My investigations of Pedi- 

 cularis and Orobanche have led me to this conclusion : the original 

 and always four-divided type is distinctly present in Veronica, in which 

 the two leaves of the innermost circle form stamens, and the two others 

 an unilateral disc*: similar conditions also occur in the allied families ; 

 and a more close investigation would include the Acanthacece, the Pe- 

 dalinece, &c., within the circle of investigation. 



D. THE RUDIMENTS OF THE 



157. The seed-bud, which is the only essential part of the 

 rudiment of the fruit, may be either naked, or enclosed in a re- 

 ceptacle, which last is termed the pistil. When it is present it 

 consists of two parts; a cavity which encloses the seed- bud, the 

 germen ; and an external opening peculiarly modified, the stigma : 

 sometimes the germen is elongated beneath the stigma into a 

 longer or shorter tube, termed the style. The seed-buds are 

 attached, at determinate places, in the germen, where a part is 

 often so characterised as to be particularly distinguished as a 

 peculiar organ. This part is called the spermophore. For the 



* In Calceolaria there are only two tetra-merous circles, the outer of which becomes 

 calyx, while in the inner the upper and lower leaf become corolla, and the two side 

 ones stamens. 



215 Pimelea decussata. A, Longitudinal section through the flower : a, pedicel ; 

 6, tube ; c, limb of the perianth ; d, two stamens; e, accessory stamens ; /, style ; g, ger- 

 men with the seed-bud. B, An accessory stamen, much magnified. 



