THE PRINCIPLE OF AEEANGEMENT. 



43 



tt. fft. 



the flower, througli which nourishment is withdrawn at 

 certain places to produce hypertrophy elsewhere. Thus the 

 sepaline cord, instead of bearing an anther in Primula, bifur- 

 cates at the angle, and each branch proceeds up the margin 

 of a lobe of the corolla, and aids in nourishing the latter. 



As a converse instance of the sepaline cord undertaking 

 a considerable amount of work, may be mentioned Gampanula 

 ■medium. In this plant the 5-lobed fibro- vascular cylinder 

 of the pedicel sends ofE five cords 

 intended for the calyx (Fig. 8, sep.) ; 

 but, before reaching the base of the 

 superior sepal, it sends ofB an inner- 

 most and lowest cord to become the 

 dorsal one of the carpel (d. car.), 

 which, in this flower, is thus super- 

 posed to a sepal. It also sends off 

 two, right and left, one for each 

 petal alternating with it (pet.) ; so 

 that each petal receives two cords, 

 one from each adjacent sepal, — a -^ 



most unnsual condition of things, O . , — vOZT^^, „, 



for petals have almost invariably /^ II \ 



their own cords issuing from the ^x n_7 ^ 



pedicel. Lastly, the same sepaline Fie- S—Vcrtical and transverae aec 



^ . tions of the wall of the inferior 



cord provides that of the stamen ovary of campanula medium 



-,^ ji-i Til- (*"*"■ ^^^ Tieghem). 



(St.) superposed to it. In this 



flower, therefore, we can understand why there is no petal- 



ine whorl of stamens ; simply because the corolla does not 



possess its own proper fibro-vascular cords to give rise to 



them. 



On the other hand, in the Malvacece after the axis has 

 supplied cords for the sepals, others furnish those of the 

 corolla ; these latter, however, by radial division form two 



^ft. 



