196 THE FLOWER. 



opposite the sepals. These organs altogether are in four whorls 

 of three, not in two of six members ; and the pistil at the centre, 

 of three combined members, is the fifth and final whorl. 



359. The Barberry family exhibits a similar seeming ante- 

 position, which is more striking on account of a multiplication 

 of the members of the perianth. The calyx is of six sepals in 

 two circles, the corolla of six petals in two circles, the stamens 

 equally six ; and so each petal has a stamen before and a sepal 

 behind it. But, when properly viewed as a trimerous flower with 

 double circles of sepals and petals as well as of stamens, all is 

 S3 r mmetrical and normal. Menispermum in the related Moonseed 

 famity is in the same case, but the flower is trimerous, as seen 

 in Fig. 369 : in the male blossom this is obscured in the androe- 

 cium (Fig. 368) by a multiplication of the stamens. 1 The 

 same thing occurs in the perianth and bracts of certain Clusiaceae, 

 in which the members counted as in fours are superposed, and 

 in some of which the double dimerous arrangement with apparent 

 anteposition extends through the corolla ; while, in other closety 

 related flowers, the corolla changes to simply tetramerous and to 

 alternation with the preceding four sepals. This passes, in the 

 same family and in the allied Ternstrosmiaceae, into 



360. Superposition by Spirals, as where five petals are ante- 

 posed to five sepals, b}* an evident continuation of pentastichous 

 ph}*llotaxy ; and the stamen-clusters of Gordonia Lasianthus 

 are probably in this way brought before the petals. 2 The flower 

 of Camellia is continuously on the spiral plan up to the gynoe- 

 cium ; but upon one which, from the bracts onward, rises from the 

 to the and f order or higher, throwing the petals of the rosette 

 in a full-double flower into numerous more or less conspicuous 

 vertical ranks. 



361. Anteposition in the Androecium. It is in the androecium 

 that real anteposition is most common, and also most difficult to 

 account for upon any one principle. Doubtless it comes to pass 

 in more than one way. This condition is chiefly noticed when 

 the stamens are definite in number, and mainly in isostemonous 

 and diplosternonous flowers. (324.) 



362. With Isostemony. Vitis (Fig. 379-381), also Rhamnus 

 (Fig. 415, 416), and the whole Grape and Buckthorn families of 



1 In Columbine (Aquilegia), multiplication of the stamens in successively 

 alternating 5-merous whorls similarly brings the andrcecium into ten ranks ; 

 so, when these stamens in double flowers are transformed into hollow-spurred 

 petals, these are set one into another hi ten vertical ranks. 



2 Gen. Illustr. ii. 1. 140. But the petals alternate with the sepals in the 

 ordinary manner of the flower, though their strong quincuncial imbrication 

 suggests the spiral arrangement. 



