118 DESCRIPTIVE BOTANY. PARTI. 



and consequently that all these parts are only analogous 

 to so many leaves, which under other circumstances 

 would have developed regularly round the branch on 

 which they grew then may every deviation from the 

 symmetrical arrangement in the parts of the flower, be 

 ascribed to the operation of certain modifying causes, 

 connected with some peculiarity, inherent in the several 

 species themselves. These causes may be arranged under 

 the heads of "Abortion," "Degeneration," and "Ad- 

 hesion." 



(115.) Abortion. This term is used, wherever some 

 organ is wanting, to complete the symmetry of the 

 flower ; in which case, such organ is supposed to lie 

 dormant under ordinary circumstances, though capa- 

 ble of development under other and peculiar condi- 

 tions. As the latter are of accidental occurrence, 

 they only give rise to those various monstrosities, or 

 deviations from the ordinary form, which are frequently 

 (as in the case of the Linaria above mentioned (art. 

 I 1 k) so valuable), in determining what is considered 

 to be the " normal " structure, or regular condition, to 

 which various unsymmetrical flowers may be referred. 

 Portions of the inner whorls are more often abortive 

 than those of the outer ; - and thus the number of carpels 

 is far less frequently in accordance with the normal 

 structure, than the number of the stamens. All uni- 

 sexual flowers, may be considered as resulting from the 

 complete abortion of one or other of the two innermost 

 whorls. 



(116.) Degeneration, is where the abortion of an 

 organ is not fully completed, but where it has become 

 imperfectly developed, or very differently modified from 

 its usual state. In many instances, we find certain 

 anomalous appendages, which occupy the place of some of 

 the subordinate parts belonging to one or other of the 

 floral whorls, and which are consequently considered as a 

 monstrous or incomplete state of those parts. Perhaps 

 the stamens are more especially subject to this condition 

 of degeneracy than any other organs. They frequently 



