124 



DESCRIPTIVE BOTANY. 



PART I. 



no real want of symmetry in the arrangement ; and 

 such a state of things is always supposed to have 

 originated in the abortion of one or more of the whorls. 

 These whorls may possibly be still developed under 

 certain conditions, and then the regularity of the 

 flower would be restored, and the normal condition ex- 

 hibited. In the annexed figure (135.) there are five 

 whorls ascribed to the normal 

 condition of certain organs, 

 which " alternate " with each 

 other in some flower; and by 

 suppressing the parts in the 

 second and fourth whorl, those 

 in the first, third, and fifth 

 are brought " opposite " to 

 each other. Where two con- 

 tiguous whorls are abortive, 

 no irregularity would be ap- 

 parent, and the existence of the suppressed parts might 

 not be suspected, unless it were indicated by some ana- 

 logy in other allied species. 



It is a remarkable circumstance connected with these 

 inquiries, that the normal condition of dicotyledonous 

 plants, appears most frequently to involve a quinary 

 arrangement, in the disposition of the subordinate 

 parts of the several whorls j whilst that of Monocoty- 

 ledons, equally affects a ternary. In a multitude of 

 examples, where the parts or organs of the class exceed 

 these numbers respectively, they are still observed to be 

 some multiples of them 10, 15, 20, &c., or 6, 9, &c.; 

 and many deviations from this rule, are clearly referable 

 to the abortions of some of the parts, and the adhesions 

 of others ; so that a considerable approximation has 

 apparently been made, towards the discovery of some 

 general laws on this subject. 



(121.) Spiral Arrangement of foliaceous Append- 

 ages. The variety exhibited in the disposition of leaves, 

 and other foliaceous appendages to the stem, or other 



