DISAPPEARANCE OF PARTS. 187 



5. DISAPPEARANCE OR OBLITERATION OF PARTS. 



342. Abortion or Suppression are somewhat synonymous terms 

 to denote the obliteration or rather non-appearance of organs 

 which belong to the plan of the blossom. Abortion is applied 

 particularly and more properly to partial obliteration, as where 

 a stamen is reduced to a naked filament, or to a mere rudiment 

 or vestige, answering to a stamen and occupying the place of 

 one, but incapable of performing its office ; suppression, to abso- 

 lute non-appearance. Such vestiges or abortive organs justify 

 the use of these terms, the more so as all gradations are some- 

 times met with between the perfect organ and the functionless 

 rudiment which occupies its place. Such obliterations, whether 

 partial or complete, may affect either a whole circle of organs 

 or merely some of its members. The former interferes with the 

 completeness of a flower, and may obscure the normal order of 

 its parts. The latter directly interferes with the symmetry of 

 the blossom, and is commonly associated with irregularh\y. 



343. Of parts of a Circle. Among papilionaceous flowers 

 (338), different species of Erythrina have all the petals but one 

 (the vexillum, Fig. 344, a) much reduced in 



size, in some concealed in the calyx, and in 

 every way to be ranked as abortive organs. 

 In Amorpha, of the same family, these four 

 petals are gone, leaving no trace, reducing 

 the corolla to a single petal. (Fig. 352, 353.) 

 This one is evidently the vexillum, both by 

 position and shape ; and the 5-merous type, 

 also the particular type of the family, are still 

 discernible in the five notches of the calyx, 

 the ten stamens, &c. In a related genus, 

 Parryella, even this last petal is wanting, and 

 the androecium is straight, all irregularity thus 

 disappearing through suppression. 



344. Delphinium or Larkspur and Aconite or Monkshood 

 furnish good examples of flowers in which irregularity is accom- 

 panied by more or less abortion. The calyx of the Larkspur 

 (Fig. 354-356) is irregular by reason of the dissimilarity of the 

 five sepals, one of which, the uppermost and largest, is pro- 

 longed posteriorly into a long and hollow spur. Within these, 

 and alternate with them as far as they go, are the petals, onry 



FIG. 352. Stamens and pistil of Amorpha fruticosa. 353. An entire flower of the 

 same. 



