80 VEGETABLE ORGANOGRAPHY. 



Section VII. 



Of Abortions of Parts of the Flower, or of their 

 Degenerations. 



All the parts of flowers may either disappear more or 

 less completely, or present themselves in unusual forms ; 

 and it is of great importance, in order to appreciate the 

 true symmetry of plants, to recognise them under their 

 different appearances ; it is this that we are now about 

 to do. very rapidly, examining first the cases where all 

 the similar parts, that is to say, those which compose 

 the same organ, undergo the same change. 



The calyx is more rarely absent than any other organ, 

 probably because its external position causes it but sel- 

 dom to suffer in its development by the pressure of 

 neighbouring organs. In plants where it is free, I only 

 know Nemopanthes in which it appears to be entirely 

 absent, or in which it is reduced to a simple, scarcely 

 apparent rim. In those where it is adherent, the tube 

 is united with the torus and ovary, so as to be hardly 

 visible ; and the limb or part not united is sometimes 

 absent. Thus, for example, in the Umbelliferae, when 

 this limb exists, it appears under the form of five little 

 teeth, as in (Enanthe ; but in a great number of cases it 

 is completely abortive, and is replaced by a small circu- 

 lar rim, analogous to that of Nemopanthes. 



When the flowers are collected into compact heads, 

 and inclosed in an involucrum, the calyx becoming as it 

 were an internal organ, and being submitted to the pres- 

 sure of the neighbouring flowers or bracts, presents 

 abortions more frequently. This is but seldom the case 

 in flowers where it is not adherent ; but Diplolama, one 



